func_code_string: #include <bits/stdc++.h>   using namespace std;   string a;   int main() {     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       cin >> a;       for (int i = 0; i < a.length(); i += 2) cout << a[i];       cout << endl;     }     return 0;   }   