func_code_string: #include <bits/stdc++.h>   using namespace std;   int c[100004], i, n, t, q, w, nr, r, d, s;   char a[100004], b[100004];   int main() {     scanf( %d %d n , &n, &t);     for (i = 1; i <= n; i++) scanf( %c , &a[i]);     scanf(  n );     for (i = 1; i <= n; i++) scanf( %c , &b[i]);     for (i = 1; i <= n; i++) {       if (a[i] == b[i]) c[++nr] = i;     }     if ((n - nr) <= t) {       for (i = 1; i <= n; i++) {         if (a[i] != b[i]) {           if (a[i] !=  a  && b[i] !=  a )             printf( a );           else if (a[i] !=  b  && b[i] !=  b )             printf( b );           else             printf( c );         } else if (r < (n - t)) {           printf( %c , a[i]);           r++;         } else {           if (a[i] !=  a )             printf( a );           else             printf( b );         }       }     } else {       q = n - nr;       if (q > (2 * t))         printf( %d , -1);       else {         s = (n - nr - t) * 2;         if (s > q)           printf( %d , s);         else {           for (i = 1; i <= n; i++) {             if (a[i] != b[i]) {               if (d < s) {                 if (d % 2 == 0)                   printf( %c , a[i]);                 else                   printf( %c , b[i]);                 d++;               } else {                 if (a[i] !=  a  && b[i] !=  a )                   printf( a );                 else if (a[i] !=  b  && b[i] !=  b )                   printf( b );                 else                   printf( c );               }             } else               printf( %c , a[i]);           }         }       }     }     return 0;   }   