func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     set<char> deputi;     vector<vector<char> > off;     int m, n;     char boss;     cin >> n >> m >> boss;     off.resize(n);     for (int i = 0; i < n; i++) off[i].resize(m);     for (int i = 0; i < n; i++)       for (int j = 0; j < m; j++) do {           cin >> off[i][j];         } while (off[i][j] ==   n );     for (int i = 0; i < n; i++)       for (int j = 0; j < m; j++)         if (off[i][j] == boss) {           if (i > 0) deputi.insert(off[i - 1][j]);           if (i < n - 1) deputi.insert(off[i + 1][j]);           if (j > 0) deputi.insert(off[i][j - 1]);           if (j < m - 1) deputi.insert(off[i][j + 1]);         }     deputi.erase( . );     deputi.erase(boss);     cout << deputi.size() << endl;   }   