diff --git a/Appendix C/solutions/15787.cpp b/Appendix C/solutions/15787.cpp
index 6c991660..58401da6 100644
--- a/Appendix C/solutions/15787.cpp	
+++ b/Appendix C/solutions/15787.cpp	
@@ -1,11 +1,33 @@
-// Authored by : BaaaaaaaaaaarkingDog
+// Authored by : uhwan0723
 // Co-authored by : -
-// http://boj.kr/****************
+// http://boj.kr/213d52a2b98146ccba8b80a28d3f2811
 #include <bits/stdc++.h>
 using namespace std;
 
+int n, m;
+
 int main(void){
   ios::sync_with_stdio(0);
   cin.tie(0);
-  
-}
\ No newline at end of file
+  cin >> n >> m;
+  vector<int> v(n, 0);
+  while(m--){
+    int com, i, x;
+    // 0-index로 쓰기 위해 i는 i-1로, x는 x-1로 사용합니다.
+    cin >> com >> i;
+    if(com == 1){
+      cin >> x;
+      v[i-1] |= (1 << (x-1));
+    }
+    else if(com == 2){
+      cin >> x;
+      v[i-1] &= ~(1 << (x-1));
+    }
+    else if(com == 3)
+      v[i-1] = (v[i-1] << 1) & ((1 << 20) - 1);
+    else
+      v[i-1] = v[i-1] >> 1;
+  }
+  sort(v.begin(), v.end());
+  cout << distance(v.begin(), unique(v.begin(), v.end()));
+}