diff --git a/Changhun-Han/src/baekjoon/greedy/BOJ_20300.java b/Changhun-Han/baekjoon/greedy/BOJ_20300.java
similarity index 100%
rename from Changhun-Han/src/baekjoon/greedy/BOJ_20300.java
rename to Changhun-Han/baekjoon/greedy/BOJ_20300.java
diff --git a/Changhun-Han/src/baekjoon/greedy/BOJ_13164.java b/Changhun-Han/src/baekjoon/greedy/BOJ_13164.java
deleted file mode 100644
index 06440898..00000000
--- a/Changhun-Han/src/baekjoon/greedy/BOJ_13164.java
+++ /dev/null
@@ -1,45 +0,0 @@
-package baekjoon.greedy;
-
-import static java.lang.Integer.parseInt;
-import static java.lang.Long.parseLong;
-import static java.util.Arrays.sort;
-
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.util.StringTokenizer;
-
-/**
- * @see
- * https://www.acmicpc.net/problem/20300
- *
- */
-public class BOJ_20300 {
- public static void main(String[] args) throws IOException {
- try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in))) {
- int N = parseInt(br.readLine());
- StringTokenizer st = new StringTokenizer(br.readLine());
-
- long[] lossMuscles = new long[N];
- for (int i = 0; i < lossMuscles.length; i++) {
- lossMuscles[i] = parseLong(st.nextToken());
- }
-
- sort(lossMuscles);
-
- long maximum = 0;
- if (N % 2 == 0) {
- for (int i = 0; i < N / 2; i++) {
- maximum = Math.max(maximum, lossMuscles[i] + lossMuscles[N - 1 - i]);
- }
- }
- else {
- maximum = lossMuscles[N - 1];
- for (int i = 0; i < (N - 1) / 2; i++) {
- maximum = Math.max(maximum, lossMuscles[i] + lossMuscles[N - 2 - i]);
- }
- }
- System.out.println(maximum);
- }
- }
-}
\ No newline at end of file
diff --git a/Jeongyo-Han/baekjoon/1700.cc b/Jeongyo-Han/baekjoon/1700.cc
new file mode 100644
index 00000000..3e88beeb
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/1700.cc
@@ -0,0 +1,56 @@
+#include
+#include
+#include
+
+using namespace std;
+int main()
+{
+ ios::sync_with_stdio(false);
+ cin.tie(NULL);
+ cout.tie(NULL);
+
+ int n, k;
+ int tmp;
+ cin >> n >> k;
+ vector input;
+ vector> idxes(k+1);
+
+ for (int i=0; i> tmp;
+ input.push_back(tmp);
+ idxes[tmp].push_back(i);
+ }
+
+ set s;
+ int ans = 0;
+ for (int i=0; i mx ) {
+ mx = idxes[j][0];
+ val = j;
+ }
+ }
+
+ s.erase(val);
+ s.insert(id);
+ idxes[id].erase(idxes[id].begin(),idxes[id].begin() +1);
+ ans++;
+ }
+ }
+ cout << ans;
+}
\ No newline at end of file
diff --git a/Jeongyo-Han/baekjoon/BOJ_10172.java b/Jeongyo-Han/baekjoon/BOJ_10172.java
new file mode 100644
index 00000000..dc2f0711
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_10172.java
@@ -0,0 +1,12 @@
+package baekjoon;
+
+public class BOJ_10172 {
+
+ public static void main(String[] args) {
+ System.out.println("|\\_/|\n"
+ + "|q p| /}\n"
+ + "( 0 )\"\"\"\\\n"
+ + "|\"^\"` |\n"
+ + "||_/=\\\\__|");
+ }
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_10797.java b/Jeongyo-Han/baekjoon/BOJ_10797.java
new file mode 100644
index 00000000..bce0114a
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_10797.java
@@ -0,0 +1,22 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_10797 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ int a = sc.nextInt();
+ int b = 0;
+
+ for(int i=0; i<5; i++) {
+ if(sc.nextInt() % 10 == a) {
+ b += 1;
+ }
+ }
+
+ System.out.println(b);
+ }
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_10817.java b/Jeongyo-Han/baekjoon/BOJ_10817.java
new file mode 100644
index 00000000..280381cb
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_10817.java
@@ -0,0 +1,28 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_10817 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ int num[] = {sc.nextInt(), sc.nextInt(), sc.nextInt()};
+ int tmp = 0;
+
+ for(int i = 0; i < 3; i++) {
+
+ for(int j = i+1; j < 3; j++) {
+
+ if(num[i] > num[j]) {
+ tmp = num[i];
+ num[i] = num[j];
+ num[j] = tmp;
+ }
+ }
+ }
+
+ System.out.println(num[2]);
+ }
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_11022.java b/Jeongyo-Han/baekjoon/BOJ_11022.java
new file mode 100644
index 00000000..85c24c60
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_11022.java
@@ -0,0 +1,21 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_11022 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ int t = sc.nextInt();
+
+ for (int i=1; i<=t; i++) {
+
+ int a = sc.nextInt();
+ int b = sc.nextInt();
+
+ System.out.println("Case #" + i + ": " + a + " + " + b + " = " + (a+b));
+ }
+ }
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_11654.java b/Jeongyo-Han/baekjoon/BOJ_11654.java
new file mode 100644
index 00000000..20c277f9
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_11654.java
@@ -0,0 +1,13 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_11654 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ System.out.println((int)sc.next().charAt(0));
+ }
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_14681.java b/Jeongyo-Han/baekjoon/BOJ_14681.java
new file mode 100644
index 00000000..6a10024b
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_14681.java
@@ -0,0 +1,18 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_14681 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ int x = sc.nextInt();
+ int y = sc.nextInt();
+
+ int n = (x>0) ? (y>0)?1:4 : (y>0)?2:3;
+
+ System.out.println(n);
+ }
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_2438.java b/Jeongyo-Han/baekjoon/BOJ_2438.java
new file mode 100644
index 00000000..af37817a
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_2438.java
@@ -0,0 +1,23 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_2438 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ int a = sc.nextInt();
+
+ for(int i=1; i<=a; i++) {
+
+ for(int j=0; ji; j--) {
+ System.out.print(" ");
+ }
+
+ for(int k=0; k60) {
+ while(m>=60) {
+ m -= 60;
+ h += 1;
+ }
+ }
+
+ if(h >= 24) {
+ h -= 24;
+ }
+
+ System.out.println(h + " " + m);
+ }
+
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_2562.java b/Jeongyo-Han/baekjoon/BOJ_2562.java
new file mode 100644
index 00000000..95caf4db
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_2562.java
@@ -0,0 +1,26 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_2562 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ int max = 0;
+ int index = 0;
+
+ for(int i = 0; i <= 9; i++) {
+
+ int a = sc.nextInt();
+
+ if(a > max) {
+ max = a;
+ index = i;
+ }
+ }
+
+ System.out.println(max + "\n" + index);
+ }
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_2577.java b/Jeongyo-Han/baekjoon/BOJ_2577.java
new file mode 100644
index 00000000..6fdd6fd6
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_2577.java
@@ -0,0 +1,26 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_2577 {
+
+ public static void main(String[] args) {
+ Scanner sc = new Scanner(System.in);
+ int A = sc.nextInt();
+ int B = sc.nextInt();
+ int C = sc.nextInt();
+ sc.close();
+
+ int[] counts = new int[10];
+ int number = A * B * C;
+ while (number > 0) {
+ counts[number % 10]++;
+ number /= 10;
+ }
+
+ for (int i = 0; i < counts.length; ++i) {
+ System.out.println(counts[i]);
+ }
+ }
+
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_2588.java b/Jeongyo-Han/baekjoon/BOJ_2588.java
new file mode 100644
index 00000000..c6512c55
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_2588.java
@@ -0,0 +1,16 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_2588 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ int a = sc.nextInt();
+ int b = sc.nextInt();
+
+ System.out.printf("%d\n%d\n%d\n%d", a*(b%10), a*(b%100/10), a*(b/100), a*b);
+ }
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_2742.java b/Jeongyo-Han/baekjoon/BOJ_2742.java
new file mode 100644
index 00000000..8bebf0d0
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_2742.java
@@ -0,0 +1,16 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_2742 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ for(int i = sc.nextInt(); i>0; i--) {
+ System.out.println(i);
+ }
+ }
+
+}
\ No newline at end of file
diff --git a/Jeongyo-Han/baekjoon/BOJ_2753.java b/Jeongyo-Han/baekjoon/BOJ_2753.java
new file mode 100644
index 00000000..8cd3978d
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_2753.java
@@ -0,0 +1,16 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_2753 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ int a = sc.nextInt();
+
+ System.out.println((a%4==0 && a%100!=0 || a%400==0) ? 1 : 0);
+ }
+
+}
diff --git a/Jeongyo-Han/baekjoon/BOJ_5543.java b/Jeongyo-Han/baekjoon/BOJ_5543.java
new file mode 100644
index 00000000..c85bd9e1
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/BOJ_5543.java
@@ -0,0 +1,23 @@
+package baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_5543 {
+
+ public static void main(String[] args) {
+
+ Scanner sc = new Scanner(System.in);
+
+ int[] bg = {sc.nextInt(), sc.nextInt(), sc.nextInt()};
+
+ int d1 = sc.nextInt();
+ int d2 = sc.nextInt();
+
+ int b = bg[0] < bg[1] ? bg[0] < bg[2] ? bg[0] : bg[2] : bg[1] < bg[2] ? bg[1] : bg[2];
+
+ int result = d1 < d2 ? b+d1-50 : b+d2-50;
+
+ System.out.println(result);
+ }
+
+}
diff --git a/Jeongyo-Han/baekjoon/test.txt b/Jeongyo-Han/baekjoon/test.txt
new file mode 100644
index 00000000..f5cb1030
--- /dev/null
+++ b/Jeongyo-Han/baekjoon/test.txt
@@ -0,0 +1 @@
+풀리퀘스트 테스트입니다
diff --git a/Seah-An/book/array/stock.py b/Seah-An/book/array/stock.py
new file mode 100644
index 00000000..ee9d8007
--- /dev/null
+++ b/Seah-An/book/array/stock.py
@@ -0,0 +1,22 @@
+from typing import List
+import sys
+
+
+class Solution(object):
+ def maxProfit(self, prices: List[int]) -> int:
+ revenue = 0
+ # typeError 방지하기 위해 최솟값은 시스템의 최댓값, 최댓값은 시스템의 최솟값으로 설정하는 것이 좋음.
+ # 시스템의 최솟값은 -sys.maxsize
+ bottom = sys.maxsize
+
+ for price in prices:
+ bottom = min(bottom, price)
+ revenue = max(revenue, price - bottom)
+
+ return revenue
+
+
+if __name__ == "__main__":
+ rs = Solution()
+ nums: List[str] = [7, 1, 5, 3, 6, 4]
+ print(rs.maxProfit(nums))
diff --git a/Seah-An/book/array/sum3.py b/Seah-An/book/array/sum3.py
new file mode 100644
index 00000000..df85b2e1
--- /dev/null
+++ b/Seah-An/book/array/sum3.py
@@ -0,0 +1,30 @@
+from typing import List
+
+
+# https://leetcode.com/problems/3sum/
+class Solution:
+
+
+ def threeSum(self, nums: List[int]) -> List[List[int]]:
+ nums.sort()
+ result = []
+
+ for i in range(len(nums) - 2):
+ if nums[i] == nums[i - 1] and i > 0:
+ continue
+ for j in range(i + 1, len(nums) - 1):
+ if nums[j] == nums[j - 1] and j > i + 1:
+ continue
+ for k in range(j + 1, len(nums)):
+ if k > j + 1 and nums[k] == nums[k - 1]:
+ continue
+ if nums[i] + nums[j] + nums[k] == 0:
+ result.append((nums[i], nums[j], nums[k]))
+
+ return result
+
+
+if __name__ == "__main__":
+ rs = Solution()
+ nums: List[str] = [-1, 0, 1, 2, -1, -4]
+ print(rs.threeSum(nums))
diff --git a/Seongeun-Kim/src/baekjoon/BOJ_5543.java b/Seongeun-Kim/src/baekjoon/BOJ_5543.java
new file mode 100644
index 00000000..7d092988
--- /dev/null
+++ b/Seongeun-Kim/src/baekjoon/BOJ_5543.java
@@ -0,0 +1,30 @@
+package baekjoon;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class BOJ_5543 {
+ public static void main(String[]args)throws IOException{
+
+ BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+ int burger = 2001;
+ int drink = 2001;
+
+ for(int i=0; i<3;i++){
+ int value = Integer.parseInt(br.readLine());
+ if(value 18:
+ print("After")
+ else:
+ print("Before")
+else:
+ print("After")
\ No newline at end of file
diff --git a/Yeonji-Choi/src/baekjoon/BOJ_2577.java b/Yeonji-Choi/src/baekjoon/BOJ_2577.java
new file mode 100644
index 00000000..c830879e
--- /dev/null
+++ b/Yeonji-Choi/src/baekjoon/BOJ_2577.java
@@ -0,0 +1,26 @@
+package src.baekjoon;
+
+import java.util.Scanner;
+
+public class BOJ_2577 {
+
+ public static void main(String[] args) {
+ Scanner sc = new Scanner(System.in);
+ int A = sc.nextInt();
+ int B = sc.nextInt();
+ int C = sc.nextInt();
+ sc.close();
+
+ int[] counts = new int[10];
+ int number = A * B * C;
+ while (number > 0) {
+ counts[number % 10]++;
+ number /= 10;
+ }
+
+ for (int i = 0; i < counts.length; ++i) {
+ System.out.println(counts[i]);
+ }
+ }
+
+}