#include <bits/stdc++.h>   using namespace std;   const int INF = 1e9 * 2;   int main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     int t;     cin >> t;     while (t--) {       int n;       cin >> n;       string s;       cin >> s;       int l = 0, r = n - 1;       while (l <= n && s[l] ==  0 ) l++;       while (r >= 0 && s[r] ==  0 ) r--;       int ans;       if (l > r)         ans = n;       else         ans = max(r + 1, n - l) * 2;       cout << ans <<   n ;     }     return 0;   }   