func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int T;     T = 1;     while (T--) {       string t, s, s1, s2;       cin >> t;       s = t;       int i, j, x, l, a = 0;       for (i = 0; i < t.length(); i++) {         if (t[i] ==  a ) a = i;       }       for (i = 0; i < t.length(); i++) {         if (t[i] ==  a ) {           t.erase(i, 1);           i--;         }       }       l = t.length();       s1 = t.substr(0, l / 2);       s2 = t.substr(l / 2, l - l / 2);       if (s1 == s2) {         for (i = 0, j = 0; j < s1.length();) {           if (s[i] !=  a ) {             i++;             j++;           } else             i++;         }         while (s[i] ==  a ) {           i++;         }         if (i > a) {           s1 = s.substr(0, i);           cout << s1 << endl;         } else           cout <<  :( n ;       } else {         cout <<  :( n ;       }     }     return 0;   }   