func_code_string: #include <bits/stdc++.h>   using namespace std;   char s1[100002], s2[100002];   int diff[100002] = {0};   int main() {     scanf( %s , s1);     scanf( %s , s2);     int i, len = strlen(s1), count = 0, temp;     for (i = 0; i < len; i++) {       if (s1[i] != s2[i]) {         diff[i] = 1;         count++;       }     }     if (count & 1)       cout <<  impossible ;     else {       temp = count >> 1;       for (i = 0; i < len; i++) {         printf( %c , s1[i]);         if (s1[i] != s2[i]) temp--;         if (temp == 0) break;       }       i++;       for (; i < len; i++) printf( %c , s2[i]);     }     return 0;   }   