func_code_string: #include <bits/stdc++.h>   using namespace std;   long long n, tmp1, tmp2, q;   string s, t;   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     cin >> q;     for (int rr = 0; rr < q; rr++) {       cin >> n >> s;       tmp1 = 0, t =   ;       while (s[tmp1] ==  0  && tmp1 < n) {         cout << 0;         tmp1++;       }       tmp2 = s.length() - 1;       while (s[tmp2] ==  1  && tmp2 >= 0) {         t +=  1 ;         tmp2--;       }       if (tmp1 < tmp2) {         cout << 0;       }       cout << t <<   n ;     }   }   