#include <bits/stdc++.h>
#define ll long long
 
using namespace std;
 
const int MOD = 1e9 + 7;
 
void solve(){
	int n;
	cin >> n;
	string s;
	cin >> s;
	int ans= 0;
	int top = 0, bottom = 0;
	for(int i = 0; i < n; i++){
		if(s[i] == '1'){
			bottom++;
			ans = max(ans, bottom);
			top = bottom;
			bottom = 0;
		}else{
			top += i;
			bottom += n - i - 1;
			ans = max({ans, top, bottom});
		}
	}
	cout << ans << "\n";
 
}
 
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
 
	int t = 1;
	cin >> t;
 
	for(int i = 1; i <= t; i++){
		solve();
	}
	return 0;
}

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NgozCjAwMAo0CjAwMTAKNwoxMDExMDAxCjQKMDAwMQoyCjExCjEKMAo=

6
3
000
4
0010
7
1011001
4
0001
2
11
1
0