diff --git a/climbing-stairs/do-heewan.py b/climbing-stairs/do-heewan.py
new file mode 100644
index 000000000..b3311a6d3
--- /dev/null
+++ b/climbing-stairs/do-heewan.py
@@ -0,0 +1,11 @@
+class Solution:
+    def climbStairs(self, n: int) -> int:
+        dp = [0] * 46
+        dp[1] = 1
+        dp[2] = 2
+
+        for i in range(3, n+1):
+            dp[i] = dp[i-1] + dp[i-2]
+
+        return dp[n] 
+
diff --git a/product-of-array-except-self/do-heewan.py b/product-of-array-except-self/do-heewan.py
new file mode 100644
index 000000000..3065f207e
--- /dev/null
+++ b/product-of-array-except-self/do-heewan.py
@@ -0,0 +1,16 @@
+class Solution:
+    def productExceptSelf(self, nums: List[int]) -> List[int]:
+        result = []
+
+        x = 1
+        for element in nums:
+            result.append(x)
+            x *= element
+
+        x = 1
+        for i in range(len(nums)-1, -1, -1):
+            result[i] *= x
+            x *= nums[i]
+
+        return result
+
diff --git a/valid-anagram/do-heewan.py b/valid-anagram/do-heewan.py
new file mode 100644
index 000000000..b4c73fb00
--- /dev/null
+++ b/valid-anagram/do-heewan.py
@@ -0,0 +1,4 @@
+class Solution:
+    def isAnagram(self, s: str, t: str) -> bool:
+        return sorted(s) == sorted(t)
+