diff --git a/wkdghdwns199/ACM-25192.py b/wkdghdwns199/ACM-25192.py
deleted file mode 100644
index 22d787c..0000000
--- a/wkdghdwns199/ACM-25192.py
+++ /dev/null
@@ -1,19 +0,0 @@
-import sys
-input = sys.stdin.readline
-N = int(input())
-emoji_using_users = set()
-time_for_emoji_use = False
-emoji_use_count = 0
-for _ in range(N):
-    chat_string = input().rstrip()
-    if chat_string == 'ENTER' :
-        if time_for_emoji_use :
-            emoji_use_count += len(emoji_using_users)
-        else :
-            time_for_emoji_use = True
-        emoji_using_users = set()
-    else :
-        emoji_using_users.add(chat_string)
-
-emoji_use_count+=len(emoji_using_users)
-print(emoji_use_count)
\ No newline at end of file
diff --git a/wkdghdwns199/ACM-26069.py b/wkdghdwns199/ACM-26069.py
deleted file mode 100644
index c24cfe0..0000000
--- a/wkdghdwns199/ACM-26069.py
+++ /dev/null
@@ -1,25 +0,0 @@
-import sys
-input = sys.stdin.readline
-N = int(input())
-dancingCheck = {}
-dancingCheck['ChongChong'] = True
-for _ in range(N):
-    left_rabbit, right_rabbit = map(str, input().split())
-    try :
-        if dancingCheck[left_rabbit]:
-            dancingCheck[right_rabbit] = True
-    except :
-        dancingCheck[left_rabbit] = False
-        
-    try :
-        if dancingCheck[right_rabbit] :
-            dancingCheck[left_rabbit] = True
-    except :
-        dancingCheck[right_rabbit] = False
-
-count=0
-for key in dancingCheck.keys():
-    if dancingCheck[key] == True:
-        count+=1
-    
-print(count)
\ No newline at end of file
diff --git a/wkdghdwns199/README.md b/wkdghdwns199/README.md
index f5b6927..4ef306e 100644
--- a/wkdghdwns199/README.md
+++ b/wkdghdwns199/README.md
@@ -21,4 +21,5 @@
 | 17차시 | 2024.03.27 | DP |  <a href="https://www.acmicpc.net/problem/9184">신나는 함수 실행</a>  | <a href="https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/68">2024.03.27</a> |
 | 18차시 | 2024.04.03 | 집합과 맵 |  <a href="https://www.acmicpc.net/problem/26069">절댓값 힙</a>  | <a href="https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/73">2024.04.03</a> |
 | 19차시 | 2024.04.07 | 조합론 |  <a href="https://www.acmicpc.net/problem/25192">인사성 밝은 곰곰이</a>  | <a href="https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/76">2024.04.07</a> |
+| 20차시 | 2024.05.02 | 그리디 |  <a href="https://school.programmers.co.kr/learn/courses/30/lessons/42862?itm_content=course14743">체육복</a>  | <a href="">2024.05.02</a> |
 
diff --git "a/wkdghdwns199/\352\267\270\353\246\254\353\224\224/\354\262\264\354\234\241\353\263\265.java" "b/wkdghdwns199/\352\267\270\353\246\254\353\224\224/\354\262\264\354\234\241\353\263\265.java"
new file mode 100644
index 0000000..6231be6
--- /dev/null
+++ "b/wkdghdwns199/\352\267\270\353\246\254\353\224\224/\354\262\264\354\234\241\353\263\265.java"
@@ -0,0 +1,31 @@
+import java.util.*;
+
+class Solution {
+    public int solution(int n, int[] lost, int[] reserve) {
+        Arrays.sort(lost);
+        Arrays.sort(reserve);
+        int answer = n-lost.length;
+        for (int i=0; i<lost.length; i++){
+            for (int j=0; j<reserve.length; j++){
+                if (lost[i] == reserve[j]){
+                    answer++;
+                    lost[i] = -1;
+                    reserve[j] = -1;
+                    break;
+                }
+            }
+        }
+        
+        for (int i=0; i<lost.length; i++){
+            for (int j=0; j<reserve.length; j++){
+                if (lost[i]-1 == reserve[j] || lost[i]+1 == reserve[j]){
+                    answer++;
+                    reserve[j]=-1;
+                    break;
+                }
+            }
+        }
+        
+        return answer;
+    }
+}
\ No newline at end of file