func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long int mod = 998244353;   const long long int MAXN = 3e3 + 5;   const long long int inf = 1e17;   int main() {     ios_base::sync_with_stdio(false);     cout.tie(0);     cin.tie(0);     ;     long long int t;     cin >> t;     while (t--) {       long long int n;       cin >> n;       vector<char> v(n);       for (int i = 0; i < n; i++) cin >> v[i];       long long int a = v.back() -  0 ;       while (a % 2 == 0) {         v.pop_back();         if (v.size() > 0)           a = v.back() -  0 ;         else           break;       }       if (v.size() < 2) {         cout <<  -1  << endl;         continue;       }       long long int sum = 0;       for (int i = 0; i < v.size(); i++) {         a = v[i] -  0 ;         sum += a;       }       if (sum % 2 == 0) {         for (auto i : v) cout << i;         cout << endl;         continue;       }       long long int ind = -1;       for (int i = v.size() - 2; i > -1; i--) {         a = v[i] -  0 ;         if (a % 2) {           ind = i;           break;         }       }       if (ind == 0 && v[1] ==  0 ) ind = -1;       if (ind != 0 && v[0] ==  0 ) ind = -1;       if (ind == -1)         cout <<  -1  << endl;       else {         for (int i = 0; i < v.size(); i++) {           if (i != ind) cout << v[i];         }         cout << endl;       }     }   }   