func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m, k, c, x, y, rem;   char a[501][501];   int v[501][501];   void dfs(int x, int y) {     if (rem == 0 || a[x][y] ==  # ) return;     if (x < 0 || x >= n || y < 0 || y >= m || v[x][y] == 1) return;     v[x][y] = 1;     rem--;     dfs(x + 1, y);     dfs(x, y + 1);     dfs(x, y - 1);     dfs(x - 1, y);   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     cin >> n >> m >> k;     for (int i = 0; i < n; i++)       for (int j = 0; j < m; j++) {         cin >> a[i][j];         if (a[i][j] ==  . ) {           c++;           if (c == 1) {             x = i;             y = j;           }         }       }     rem = c - k;     dfs(x, y);     for (int i = 0; i < n; i++) {       for (int j = 0; j < m; j++) {         if (v[i][j] == 0 && a[i][j] ==  . )           cout <<  X ;         else           cout << a[i][j];       }       cout <<   n ;     }   }   