diff --git a/src/week4/BOJ11723/BOJ11723_V1.cpp b/src/week4/BOJ11723/BOJ11723_V1.cpp
new file mode 100644
index 0000000..e0c62d6
--- /dev/null
+++ b/src/week4/BOJ11723/BOJ11723_V1.cpp
@@ -0,0 +1,53 @@
+#include <bits/stdc++.h>
+using namespace std;
+int ret;
+void solve(string s, int num) {
+    if (s == "add") {
+        ret |= (1 << num);
+    } else if (s == "remove") {
+        ret &= ~(1 << num);
+    } else if (s == "check") {
+        if (ret & (1 << num)) cout << 1 << '\n';
+        else cout << 0 << '\n';
+    } else if (s == "toggle") {
+        ret ^= (1 << num);
+    } else if (s == "all") {
+        for (int i=1; i<=20; i++) {
+            ret |= (1 << i);
+        }
+    } else {
+        ret = 0;
+    }
+}
+int main() {
+
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+
+    int n;
+    cin >> n;
+
+    vector<pair<string,int>> inp;
+    for (int i = 0; i < n; i++) {
+        string s;
+        int num;
+        cin >> s;
+        if (s == "all" || s == "empty") {
+            inp.push_back({s, 0});
+        } else {
+            cin >> num;
+            inp.push_back({s, num});
+        }
+    }
+
+    for (int i = 0; i < n; i++) {
+        solve(inp[i].first, inp[i].second);
+    }
+
+
+
+
+
+    return 0;
+}
\ No newline at end of file