func_code_string: #include <bits/stdc++.h>   using namespace std;   const int inf = (1 << 29);   int n, k;   string str[2505][4], rhy[2505];   int sch[4];   string sub(string s, int k) {     string res =   ;     int t = k;     for (int i = s.size() - 1; i >= 0; --i) {       res = s[i] + res;       if (s[i] ==  a  || s[i] ==  e  || s[i] ==  i  || s[i] ==  o  ||           s[i] ==  u ) {         --t;         if (t == 0) {           break;         }       }     }     if (t != 0) {       return   ;     }     return res;   }   string find_rhy(int i) {     if (str[i][0] == str[i][1] && str[i][1] == str[i][2] &&         str[i][0] == str[i][3]) {       return  aaaa ;     }     if (str[i][0] == str[i][1] && str[i][2] == str[i][3]) {       return  aabb ;     }     if (str[i][0] == str[i][2] && str[i][1] == str[i][3]) {       return  abab ;     }     if (str[i][0] == str[i][3] && str[i][1] == str[i][2]) {       return  abba ;     }     return  NO ;   }   int main() {     ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);     cin >> n >> k;     bool f = 1;     for (int i = 0; i < n; ++i) {       for (int j = 0; j < 4; ++j) {         string s;         cin >> s;         str[i][j] = sub(s, k);         if (str[i][j] ==   ) {           f = 0;         }       }     }     if (f == 0) {       cout <<  NO n ;       exit(0);     }     for (int i = 0; i < n; ++i) {       rhy[i] = find_rhy(i);     }     string ans = rhy[0];     for (int i = 1; i < n; ++i) {       if (ans ==  aaaa ) {         ans = rhy[i];       } else if (ans == rhy[i] || rhy[i] ==  aaaa ) {         ;       } else {         ans =  NO ;       }     }     cout << ans <<   n ;     return 0;   }   