func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(false);     cin.tie(nullptr);     string s;     cin >> s;     size_t pos1 = s.find( AB ), pos2 = s.find( BA );     string tmp = s;     s.erase(0, pos1 + 2);     tmp.erase(0, pos2 + 2);     bool check = false;     if (pos1 == string::npos || pos2 == string::npos) {       cout <<  NO ;     } else {       if (s.find( BA ) != string::npos || tmp.find( AB ) != string::npos)         check = true;       if (check)         cout <<  YES ;       else         cout <<  NO ;     }     return 0;   }   