func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n = 0;     char ch;     vector<bool> v(26, 0);     while (cin >> ch) {       cin >> ch;       if (ch ==  {  || ch ==  }  || ch ==  ,  || ch ==    ) continue;       ch -= 97;       if (!v[ch]) {         v[ch] = true;         n++;       }     }     cout << n;   }   