diff --git a/YIM2UL2ET/README.md b/YIM2UL2ET/README.md
index 32219bb..170c23b 100644
--- a/YIM2UL2ET/README.md
+++ b/YIM2UL2ET/README.md
@@ -13,5 +13,4 @@
 | 09차시 | 2024.03.07 |  임의 정밀도 / 큰 수 연산 && 재귀  | [BOJ 1914](https://www.acmicpc.net/problem/1914)  | [BOJ 1914 풀이](https://github.com/AlgoLeadMe/AlgoLeadMe-7/pull/29) |
 | 10차시 | 2024.03.10 |  스택  | [BOJ 1406](https://www.acmicpc.net/problem/1406)  | [BOJ 1406 풀이](https://github.com/AlgoLeadMe/AlgoLeadMe-7/pull/31) |
 | 11차시 | 2024.03.18 |  스택  | [BOJ 1918](https://www.acmicpc.net/problem/1918)  | [BOJ 1918 풀이](https://github.com/AlgoLeadMe/AlgoLeadMe-7/pull/36) |
-| 12차시 | 2024.03.28 |  비트마스킹  | [BOJ 11723](https://www.acmicpc.net/problem/11723)  | [BOJ 11723 풀이](https://github.com/AlgoLeadMe/AlgoLeadMe-7/pull/39) |
 ---
diff --git "a/YIM2UL2ET/\353\271\204\355\212\270\353\247\210\354\212\244\355\202\271/12\354\260\250\354\213\234 - BOJ 11723.cpp" "b/YIM2UL2ET/\353\271\204\355\212\270\353\247\210\354\212\244\355\202\271/12\354\260\250\354\213\234 - BOJ 11723.cpp"
deleted file mode 100644
index c7b96fd..0000000
--- "a/YIM2UL2ET/\353\271\204\355\212\270\353\247\210\354\212\244\355\202\271/12\354\260\250\354\213\234 - BOJ 11723.cpp"	
+++ /dev/null
@@ -1,36 +0,0 @@
-#include <iostream>
-
-int main(void)
-{
-    std::ios_base::sync_with_stdio(false);
-    std::cin.tie(NULL);
-    std::cout.tie(NULL);
-
-    int n, k, bits = 0;
-    std::string command;
-    
-    std::cin >> n;
-    for (int i = 0; i < n; i++) {
-        std::cin >> command;
-        if (command == "add") {
-            std::cin >> k;
-            bits |= (1<<k);
-        }
-        else if (command == "remove") {
-            std::cin >> k;
-            bits &= ~(1<<k);
-        }
-        else if (command == "check") {
-            std::cin >> k;
-            if (bits & (1<<k)) std::cout << "1\n";
-            else std::cout << "0\n";
-        }
-        else if (command == "toggle") {
-            std::cin >> k;
-            bits ^= (1<<k);
-        }
-        else if (command == "all") bits = (1<<21)-1;
-        else bits = 0;
-    }
-    return 0;
-}
\ No newline at end of file