diff --git "a/Seol-Munhyeok/.cph/.\354\240\234\352\263\261\354\210\230\354\260\276\352\270\260.py_ea7559ebea594486c87e81b9ee32f04b.prob" "b/Seol-Munhyeok/.cph/.\354\240\234\352\263\261\354\210\230\354\260\276\352\270\260.py_ea7559ebea594486c87e81b9ee32f04b.prob"
new file mode 100644
index 0000000..48038c1
--- /dev/null
+++ "b/Seol-Munhyeok/.cph/.\354\240\234\352\263\261\354\210\230\354\260\276\352\270\260.py_ea7559ebea594486c87e81b9ee32f04b.prob"
@@ -0,0 +1 @@
+{"name":"Local: 제곱수찾기","url":"d:\\AlgoLeadME-15\\AlgoLeadMe-15\\Seol-Munhyeok\\제곱수찾기.py","tests":[{"id":1755608679338,"input":"2 3\n123\n456","output":"64"},{"id":1755610569758,"input":"9 9\n257240281\n197510846\n014345401\n035562575\n974935632\n865865933\n684684987\n768934659\n287493867","output":"95481"},{"id":1755613365657,"input":"1 1\n1","output":""},{"id":1755613442978,"input":"1 2\n12","output":""}],"interactive":false,"memoryLimit":1024,"timeLimit":3000,"srcPath":"d:\\AlgoLeadME-15\\AlgoLeadMe-15\\Seol-Munhyeok\\제곱수찾기.py","group":"local","local":true}
\ No newline at end of file
diff --git "a/Seol-Munhyeok/30\353\262\210" "b/Seol-Munhyeok/30\353\262\210"
new file mode 100644
index 0000000..4fb7649
--- /dev/null
+++ "b/Seol-Munhyeok/30\353\262\210"
@@ -0,0 +1,7 @@
+t = int(input())
+for _ in range(t):
+    a, b = map(int, input().split())
+    while a != b:
+        if a > b: a //= 2
+        else: b //= 2
+    print(10 * a)
\ No newline at end of file
diff --git a/Seol-Munhyeok/README.md b/Seol-Munhyeok/README.md
index 5f4f0a5..b85607b 100644
--- a/Seol-Munhyeok/README.md
+++ b/Seol-Munhyeok/README.md
@@ -13,4 +13,7 @@
 | 17차시 | 2025.08.01 | 구현, 시뮬레이션, 백트래킹 | [청소년 상어](https://www.acmicpc.net/problem/19236) | https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/61 |
 | 18차시 | 2025.08.05 | 브루트포스, 애드 혹, 홀짝성 | [램프](https://www.acmicpc.net/problem/1034) | https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/62 |
 | 19차시 | 2025.08.10 | 구현, BFS | [거리두기 확인하기](https://school.programmers.co.kr/learn/courses/30/lessons/81302) | https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/67 |
-| 20차시 | 2025.08.14 | DP | [코딩 테스트 공부](https://school.programmers.co.kr/learn/courses/30/lessons/118668) | https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/73 |
\ No newline at end of file
+| 20차시 | 2025.08.14 | DP | [코딩 테스트 공부](https://school.programmers.co.kr/learn/courses/30/lessons/118668) | https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/73 |
+AlgoLeadMe/AlgoLeadMe-15/pull/67 |
+| 21차시 | 2025.08.18 | 시뮬레이션, 그리디 | [양궁 대회](https://school.programmers.co.kr/learn/courses/30/lessons/92342) | https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/75 |
+| 22차시 | 2025.08.23 | 그리디, 투 포인터 | [두 큐 합 같게 만들기](https://school.programmers.co.kr/learn/courses/30/lessons/118667) | https://github.com/AlgoLeadMe/AlgoLeadMe-15/pull/79 |
\ No newline at end of file
diff --git "a/Seol-Munhyeok/\353\221\220\355\201\220\355\225\251\352\260\231\352\262\214\353\247\214\353\223\244\352\270\2601.py" "b/Seol-Munhyeok/\353\221\220\355\201\220\355\225\251\352\260\231\352\262\214\353\247\214\353\223\244\352\270\2601.py"
new file mode 100644
index 0000000..160d420
--- /dev/null
+++ "b/Seol-Munhyeok/\353\221\220\355\201\220\355\225\251\352\260\231\352\262\214\353\247\214\353\223\244\352\270\2601.py"
@@ -0,0 +1,26 @@
+from collections import deque
+
+def solution(queue1, queue2):
+    q1, q2 = deque(queue1), deque(queue2)
+    sum1, sum2 = sum(q1), sum(q2)
+
+    if (sum1 + sum2) % 2 == 1:
+        return -1
+    
+    n = len(q1)
+    for i in range(4*n+1):
+        if sum1 > sum2:
+            value = q1.popleft()
+            q2.append(value)
+            sum1 -= value
+            sum2 += value
+        elif sum1 < sum2:
+            value = q2.popleft()
+            q1.append(value)
+            sum2 -= value
+            sum1 += value
+        else:
+            return i
+        
+    return -1
+    
\ No newline at end of file
diff --git "a/Seol-Munhyeok/\353\221\220\355\201\220\355\225\251\352\260\231\352\262\214\353\247\214\353\223\244\352\270\2602.py" "b/Seol-Munhyeok/\353\221\220\355\201\220\355\225\251\352\260\231\352\262\214\353\247\214\353\223\244\352\270\2602.py"
new file mode 100644
index 0000000..07c1ffa
--- /dev/null
+++ "b/Seol-Munhyeok/\353\221\220\355\201\220\355\225\251\352\260\231\352\262\214\353\247\214\353\223\244\352\270\2602.py"
@@ -0,0 +1,30 @@
+# 투 포인터 풀이
+# https://blog.encrypted.gg/1076 를 참고함
+
+def solution(queue1, queue2):
+    n = len(queue1)
+    a = queue1 + queue2
+    target = sum(a)
+    if target % 2 != 0:
+        return -1
+    target //= 2 # 합이 target이 되는 구간을 찾아야 함
+    
+    ans = int(1e9) # 일단 매우 큰 값을 넣어놓고 시작
+    en = 0
+    tot = a[0] # 현재 보는 구간의 합 = a[st]+...+a[en], 범위가 양 끝을 포함(inclusive)한다는 점과 en < st일 땐 a[st]+...+a[2*n-1]+a[0]+...+a[en]을 나타냄에 주의
+    for st in range(2*n):
+        while tot < target:
+            en = (en + 1) % (2*n)
+            tot += a[en]
+        
+        # while문을 탈출하면 a[st]+...+a[en] 구간의 합이 target 이상임을 의미
+        if tot == target: # 구간의 합이 정확히 target과 일치할 경우
+            moves = 0 # 작업 횟수
+            if en < n-1: moves = 3*n + 1 + st + en # 3n+1번의 연산을 통해 큐1에 첫 번째 원소만 남길 수 있고, 이후 st+en 번의 추가적인 연산을 거쳐 a[st] .. a[en]을 큐1에 둘 수 있음
+            else: moves = st + (en - n + 1)
+            ans = min(ans, moves)
+        
+        tot -= a[st]
+    
+    if ans == int(1e9): ans = -1
+    return ans
\ No newline at end of file
diff --git "a/Seol-Munhyeok/\354\226\221\352\266\201\353\214\200\355\232\214.py" "b/Seol-Munhyeok/\354\226\221\352\266\201\353\214\200\355\232\214.py"
new file mode 100644
index 0000000..47504be
--- /dev/null
+++ "b/Seol-Munhyeok/\354\226\221\352\266\201\353\214\200\355\232\214.py"
@@ -0,0 +1,38 @@
+def get_points(a, r):
+    a_point, r_point = 0, 0
+    for i in range(11):
+        if a[i] == r[i] == 0: continue
+        if a[i] >= r[i]:
+            a_point += (10 - i)
+        else:
+            r_point += (10 - i)
+    return (a_point, r_point)
+ 
+def get_combinations(n, r, cur):
+    # 마지막일 때는 n을 추가
+    if r == 1:
+        return [cur + [n]]
+    
+    results = []
+    for i in range(n + 1):
+        results += get_combinations(n - i, r - 1, cur + [i])
+        
+    return results
+    
+    
+def solution(n, info):
+    answer = []
+    max_point = 0
+    cands = get_combinations(n, 11, [])
+    sorted_cands = sorted(cands, key=lambda x: tuple(x[::-1]), reverse=True)
+    
+    for cand in sorted_cands:
+        a_point, r_point = get_points(info, cand)
+        if a_point >= r_point: continue
+        
+        diff = r_point - a_point
+        if  diff > max_point:
+            max_point = diff
+            answer = cand
+    
+    return answer if answer else [-1]
\ No newline at end of file
diff --git "a/Seol-Munhyeok/\354\240\234\352\263\261\354\210\230\354\260\276\352\270\260.py" "b/Seol-Munhyeok/\354\240\234\352\263\261\354\210\230\354\260\276\352\270\260.py"
new file mode 100644
index 0000000..fefb98c
--- /dev/null
+++ "b/Seol-Munhyeok/\354\240\234\352\263\261\354\210\230\354\260\276\352\270\260.py"
@@ -0,0 +1,33 @@
+import math 
+
+answer = -1
+
+def is_square(n):
+    return math.isqrt(n) ** 2 == n
+
+def brute():
+    global answer
+    if n == 1 and m == 1:
+        return A[0][0] if is_square(int(A[0][0])) else -1
+    
+    for r0 in range(n):
+        for c0 in range(m):
+            for dr in range(-(n-1), n):
+                for dc in range(-(m-1), m):
+                    if dr == 0 and dc == 0:
+                        continue
+                    r, c = r0, c0
+                    num = ""
+                    while 0 <= r < n and 0 <= c < m:
+                        num += A[r][c]
+                        val = int(num)
+                        if is_square(val):
+                            answer = max(answer, val)
+                        r += dr
+                        c += dc
+    return answer
+
+n, m = map(int, input().split())
+A = [list(input()) for _ in range(n)]
+
+print(brute())
\ No newline at end of file