diff --git a/.DS_Store b/.DS_Store
new file mode 100644
index 0000000..4eccaf6
Binary files /dev/null and b/.DS_Store differ
diff --git a/main.ipynb b/main.ipynb
index b05630a..30ef29c 100644
--- a/main.ipynb
+++ b/main.ipynb
@@ -20,7 +20,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 3,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -37,57 +37,103 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 4,
    "metadata": {},
    "outputs": [],
    "source": [
     "def greater(a,b):\n",
-    "#your code here"
+    "    if a > b:\n",
+    "        return a\n",
+    "    else:\n",
+    "        return b\n",
+    "    "
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.563s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_greater(greater)"
    ]
   },
   {
-   "cell_type": "code",
-   "execution_count": null,
+   "cell_type": "markdown",
    "metadata": {},
-   "outputs": [],
    "source": [
-    "#your code here"
+    "## 2. Now write a function that returns the largest element on a list"
    ]
   },
   {
-   "cell_type": "markdown",
+   "cell_type": "code",
+   "execution_count": 6,
    "metadata": {},
+   "outputs": [],
    "source": [
-    "## 2. Now write a function that returns the largest element on a list"
+    "def largest_num(lst):\n",
+    "    largest = lst[0]\n",
+    "    for num in lst:\n",
+    "        if num > largest:\n",
+    "            largest = num \n",
+    "\n",
+    "        return largest\n",
+    "\n",
+    "\n",
+    "\n"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 7,
    "metadata": {},
    "outputs": [],
    "source": [
-    "#your code here"
+    "def largest_in_list(numbers):\n",
+    "    # assume the first element is the largest to start\n",
+    "    largest = numbers[0]\n",
+    "\n",
+    "    # loop through the list and update largest if we find a bigger number\n",
+    "    for num in numbers:\n",
+    "        if num > largest:\n",
+    "            largest = num\n",
+    "\n",
+    "    return largest"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 8,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.396s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
-    "test_greatest(greatest)"
+    "test_greatest(largest_in_list)"
    ]
   },
   {
@@ -99,21 +145,37 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 9,
    "metadata": {},
    "outputs": [],
    "source": [
-    "def sum_all(lst):\n",
-    "#your code here"
+    "def sum_all(numbers):\n",
+    "    total = 0\n",
+    "    for num in numbers:\n",
+    "        total += num\n",
+    "\n",
+    "    return total\n"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 10,
    "metadata": {
     "scrolled": true
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.582s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_sum(sum_all)"
@@ -128,21 +190,37 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 11,
    "metadata": {},
    "outputs": [],
    "source": [
     "def mult_all(lst):\n",
-    "#your code here"
+    "    product = 1  # start from 1 because multiplying by 0 would always give 0\n",
+    "    \n",
+    "    for num in lst:\n",
+    "        product *= num\n",
+    "    return product"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 12,
    "metadata": {
     "scrolled": true
    },
-   "outputs": [],
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.369s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_mult(mult_all)"
@@ -157,19 +235,43 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 13,
    "metadata": {},
    "outputs": [],
    "source": [
     "def oper_all(arr, oper = \"*\"):\n",
-    "#your code here"
+    "\n",
+    "    if oper == \"+\":\n",
+    "        total = 0\n",
+    "        for num in arr:\n",
+    "            total += num\n",
+    "        return total\n",
+    "    elif oper == \"*\":\n",
+    "        product = 1\n",
+    "        for num in arr:\n",
+    "            product *= num\n",
+    "        return product\n",
+    "    else:\n",
+    "        return \"Invalid operator\"\n"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 14,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.576s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_operations(oper_all)"
@@ -184,17 +286,24 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 15,
    "metadata": {},
    "outputs": [],
    "source": [
     "def factorial(n):\n",
-    "#your code here"
+    "    \n",
+    "    if n < 0:\n",
+    "        return \"Factorial not defined for negative numbers\"\n",
+    "    \n",
+    "    result = 1\n",
+    "    for i in range(1, n + 1):\n",
+    "        result *= i\n",
+    "    return result"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 16,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -213,9 +322,21 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 17,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.530s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_factorial(factorial)"
@@ -232,19 +353,35 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 18,
    "metadata": {},
    "outputs": [],
    "source": [
     "def unique(lst_un):\n",
-    "#your code here"
+    "    unique_list = []\n",
+    "    for item in lst_un:\n",
+    "        if item not in unique_list:\n",
+    "            unique_list.append(item)\n",
+    "    return unique_list"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 19,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.687s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_unique(unique)"
@@ -260,19 +397,48 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 20,
    "metadata": {},
    "outputs": [],
    "source": [
     "def mode_counter(arr):\n",
-    "#your code here"
+    "    freq = {}\n",
+    "\n",
+    "    for item in arr:\n",
+    "        if item in freq:\n",
+    "            freq[item] += 1\n",
+    "        else:\n",
+    "            freq[item] = 1\n",
+    "\n",
+    "    max_count = 0\n",
+    "    mode_value = None\n",
+    "\n",
+    "    for key in freq:\n",
+    "        if freq[key] > max_count:\n",
+    "            max_count = freq[key]\n",
+    "            mode_value = key\n",
+    "\n",
+    "    return mode_value\n",
+    "    "
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 21,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.498s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_mode(mode_counter)"
@@ -288,19 +454,53 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 22,
    "metadata": {},
    "outputs": [],
    "source": [
     "def st_dev(list_sd):\n",
-    "#your code here"
+    "    \n",
+    "    # 1 Calculate the length manually\n",
+    "    n = 0\n",
+    "    for _ in list_sd:\n",
+    "        n += 1\n",
+    "\n",
+    "    # 2 Calculate the mean manually\n",
+    "    total = 0\n",
+    "    for x in list_sd:\n",
+    "        total += x\n",
+    "    mean = total / n\n",
+    "\n",
+    "    # 3 Calculate the sum of squared differences\n",
+    "    squared_diff_sum = 0\n",
+    "    for x in list_sd:\n",
+    "        squared_diff_sum += (x - mean) ** 2\n",
+    "\n",
+    "    # 4 Apply Bessel's correction (divide by n - 1)\n",
+    "    variance = squared_diff_sum / (n - 1)\n",
+    "\n",
+    "    # 5 Standard deviation is the square root of variance\n",
+    "    std_dev = variance ** 0.5\n",
+    "    return std_dev"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 23,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.500s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_stdev(st_dev)"
@@ -315,19 +515,59 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 24,
    "metadata": {},
    "outputs": [],
    "source": [
     "def pangram(string):\n",
-    "#your code here"
+    "\n",
+    "    # 1 Convert letters to lowercase, to check case sensitive\n",
+    "    string = string.lower()\n",
+    "\n",
+    "    # 2 Keep track of letters we've seen\n",
+    "    letters_seen = []\n",
+    "\n",
+    "    # 3 Go through each character and store it if it's a letter a-z\n",
+    "    for ch in string:\n",
+    "            if \"a\" <= ch <= \"z\" and ch not in letters_seen:\n",
+    "                  letters_seen.append(ch)\n",
+    "\n",
+    "    # 4 Count letters \n",
+    "    count = 0\n",
+    "    for _ in letters_seen:\n",
+    "          count += 1\n",
+    "\n",
+    "    # 5 Check if we saw all 26 letters\n",
+    "    if count == 26:\n",
+    "        return True\n",
+    "    else:\n",
+    "        return False "
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 25,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "."
+     ]
+    },
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      ".............................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 30 tests in 0.128s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_pangram(pangram)"
@@ -344,19 +584,71 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 26,
    "metadata": {},
    "outputs": [],
    "source": [
     "def sort_alpha(string):\n",
-    "#your code here"
+    "\n",
+    "    # 1) Manually split by commas (no split)\n",
+    "    words = []\n",
+    "    current = \"\"\n",
+    "    for ch in string:\n",
+    "        if ch == \",\":\n",
+    "            words += [current]   # avoiding append()\n",
+    "            current = \"\"\n",
+    "        else:\n",
+    "            current += ch\n",
+    "    words += [current]  # add the last token\n",
+    "\n",
+    "    # 2) Compute length manually (no len)\n",
+    "    n = 0\n",
+    "    for _ in words:\n",
+    "        n += 1\n",
+    "\n",
+    "    # 3) Bubble sort (no sorted)\n",
+    "    i = 0\n",
+    "    while i < n:\n",
+    "        j = 0\n",
+    "        limit = n - i - 1\n",
+    "        while j < limit:\n",
+    "            if words[j] > words[j + 1]:\n",
+    "                tmp = words[j]\n",
+    "                words[j] = words[j + 1]\n",
+    "                words[j + 1] = tmp\n",
+    "            j += 1\n",
+    "        i += 1\n",
+    "\n",
+    "    # 4) Rebuild the CSV string (no join)\n",
+    "    result = \"\"\n",
+    "    idx = 0\n",
+    "    last = n - 1\n",
+    "    while idx < n:\n",
+    "        result += words[idx]\n",
+    "        if idx < last:\n",
+    "            result += \",\"\n",
+    "        idx += 1\n",
+    "\n",
+    "    return result\n"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 27,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.588s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_alpha(sort_alpha)"
@@ -371,19 +663,58 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 30,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "True\n",
+      "False\n",
+      "False\n",
+      "False\n"
+     ]
+    }
+   ],
    "source": [
     "def check_pass(password):\n",
-    "#your code here"
+    "    if len(password) < 8:\n",
+    "        return False\n",
+    "\n",
+    "    has_lower = any(c.islower() for c in password)\n",
+    "    has_upper = any(c.isupper() for c in password)\n",
+    "    has_digit = any(c.isdigit() for c in password)\n",
+    "    has_special = any(not c.isalnum() for c in password)  # not letter or number\n",
+    "\n",
+    "    return all([has_lower, has_upper, has_digit, has_special])\n",
+    "\n",
+    "\n",
+    "# Examples\n",
+    "print(check_pass(\"StrongPass1!\"))  # ✅ True\n",
+    "print(check_pass(\"weakpass\"))      # ❌ False\n",
+    "print(check_pass(\"HELLO123\"))      # ❌ False\n",
+    "print(check_pass(\"Hi!2\"))          # ❌ False\n",
+    "\n"
    ]
   },
   {
    "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
+   "execution_count": 31,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "....................................................................................................\n",
+      "----------------------------------------------------------------------\n",
+      "Ran 100 tests in 0.400s\n",
+      "\n",
+      "OK\n"
+     ]
+    }
+   ],
    "source": [
     "# This will test your function \n",
     "test_pass(check_pass)"
@@ -392,7 +723,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": "Python 3 (ipykernel)",
+   "display_name": "base",
    "language": "python",
    "name": "python3"
   },
@@ -406,12 +737,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.9.13"
-  },
-  "vscode": {
-   "interpreter": {
-    "hash": "aee8b7b246df8f9039afb4144a1f6fd8d2ca17a180786b69acc140d282b71a49"
-   }
+   "version": "3.13.5"
   }
  },
  "nbformat": 4,
diff --git a/mod/__pycache__/testing.cpython-313.pyc b/mod/__pycache__/testing.cpython-313.pyc
new file mode 100644
index 0000000..b01c0c4
Binary files /dev/null and b/mod/__pycache__/testing.cpython-313.pyc differ