func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MOD = 10;   const double eps = 1e-5;   const int maxN = 1100;   const int inf = 1e9 + 100;   int n, m, k;   bool vis[maxN][maxN];   inline void init() {     int a, b;     cin >> n >> m >> k;     for (int i = 0; i < k; i++) {       cin >> a >> b;       a--;       b--;       vis[a][b] = 1;       bool br = false;       if (a > 0 && b > 0 && vis[a - 1][b - 1] && vis[a - 1][b] && vis[a][b - 1])         br = true;       if (a < n - 1 && b > 0 && vis[a + 1][b - 1] && vis[a + 1][b] &&           vis[a][b - 1])         br = true;       if (a > 0 && b < m - 1 && vis[a - 1][b + 1] && vis[a - 1][b] &&           vis[a][b + 1])         br = true;       if (a < n - 1 && b < m - 1 && vis[a + 1][b + 1] && vis[a + 1][b] &&           vis[a][b + 1])         br = true;       if (br) {         cout << i + 1;         return;       }     }     cout << 0;   }   inline void solve() {}   int main() {     ios_base::sync_with_stdio(0);     init();     solve();     return 0;   }   