#include <bits/stdc++.h>   using namespace std;   string s;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     ;     long long int TESTS, k, a, n, b, c, d, m, x, i, y, z;     cin >> TESTS;     while (TESTS--) {       cin >> n;       cin >> s;       long long int ans = n;       for (long long int i = 0; i <= n - 1; i++) {         if (s[i] ==  1 ) {           a = max(i + 1, n - i);           ans = max(ans, 2 * a);         }       }       cout << ans <<   n ;     }     return 0;   }   