func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     for (int i = 0; i < t; ++i) {       int n;       cin >> n;       string s;       cin >> s;       int sum(0), pos(-1), pos1(-1), ot(-1), num(0);       for (int i = 0; i < s.length(); ++i) sum += (s[i] -  0 );       for (int i = 0; i < s.length(); ++i) {         if ((s[i] -  0 ) % 2) {           pos = i;           num = s[i] -  0 ;         }       }       for (int i = 0; i < s.length(); ++i) {         if ((s[i] -  0 ) % 2 == 0)           pos1 = i;         else if ((s[i] -  0 ) % 2 && i != pos)           ot = s[i] -  0 ;       }       if (n == 1 || pos == -1)         cout << -1 <<   n ;       else if (pos1 == -1) {         if (n % 2 == 0)           cout << s <<   n ;         else {           s.erase(s.begin() + 0);           cout << s <<   n ;         }       } else if (ot != -1)         cout << ot * 10 + num <<   n ;       else if (ot == -1)         cout << -1 <<   n ;     }   }   