func_code_string: #include <bits/stdc++.h>   using namespace std;   int n, m, k, dotx, doty;   char t[502][502];   int vis[502][502];   int x[4] = {0, -1, 0, 1};   int y[4] = {1, 0, -1, 0};   void dfs(int r, int c) {     if (r >= n || r < 0 || c >= m || c < 0 || t[r][c] ==  #  || vis[r][c]) return;     vis[r][c] = 1;     for (int i = 0; i < 4; i++) {       dfs(r + x[i], c + y[i]);     }     if (k > 0) {       k--;       t[r][c] =  X ;     }   }   int main() {     cin >> n >> m >> k;     for (int i = 0; i < n; i++)       for (int j = 0; j < m; j++) {         cin >> t[i][j];         if (t[i][j] ==  . ) {           dotx = i;           doty = j;         }       }     dfs(dotx, doty);     for (int i = 0; i < n; i++) {       for (int j = 0; j < m; j++) {         cout << t[i][j];       }       cout <<   n ;     }   }   