func_code_string: #include <bits/stdc++.h>   using namespace std;   enum { AABB, ABAB, ABBA, AAAA };   int n, k;   string s1, s2, s3, s4;   bool isvow(char c) {     return (c ==  a  || c ==  e  || c ==  i  || c ==  o  || c ==  u );   }   string suf(string s) {     static int sp = 0;     auto i = s.end(), beg = s.begin();     int tk = 0;     while (tk < k && i > beg) {       --i;       tk += isvow(*i);     }     string res(i, s.end());     if (tk < k) {       res = string(sp++,    );     }     return res;   }   void foo() {     cout <<  NO n ;     exit(0);   }   int main(void) {     int i;     cin >> n >> k;     int ans = AAAA;     for (i = 0; i < n; ++i) {       cin >> s1 >> s2 >> s3 >> s4;       auto suf1 = suf(s1), suf2 = suf(s2), suf3 = suf(s3), suf4 = suf(s4);       if (suf1 == suf2 && suf2 == suf3 && suf3 == suf4) {       } else if (suf1 == suf2 && suf3 == suf4) {         if (ans == AAAA || ans == AABB) {           ans = AABB;         } else {           foo();         }       } else if (suf1 == suf3 && suf2 == suf4) {         if (ans == AAAA || ans == ABAB) {           ans = ABAB;         } else {           foo();         }       } else if (suf1 == suf4 && suf2 == suf3) {         if (ans == AAAA || ans == ABBA) {           ans = ABBA;         } else {           foo();         }       } else {         foo();       }     }     switch (ans) {       case AABB:         cout <<  aabb n ;         break;       case ABAB:         cout <<  abab n ;         break;       case ABBA:         cout <<  abba n ;         break;       case AAAA:         cout <<  aaaa n ;         break;       default:         foo();     }     return 0;   }   