func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     string s;     cin >> s;     map<char, int> m;     vector<int> v;     for (int i = 0; i < s.size(); i++) {       m[s[i]]++;     }     map<char, int>::iterator it = m.begin();     while (it != m.end()) {       v.push_back((*it).second);       it++;     }     if (v.size() > 4 || v.size() == 1) {       cout <<  No ;     } else if (v.size() == 4) {       cout <<  Yes ;     } else if (v.size() == 3) {       if (v[0] > 1 || v[1] > 1 || v[2] > 1)         cout <<  Yes ;       else         cout <<  No ;     } else if (v.size() == 2) {       if (v[0] > 1 && v[1] > 1)         cout <<  Yes ;       else         cout <<  No ;     }     return 0;   }   