#include <bits/stdc++.h>
using namespace std;
 
int main() {
	int t;
	cin >> t;
	while(t--)
	{
		int n,c=0;
		cin >> n;
		vector<int> v,p;
		for(int i=0;i<n;i++)
		{
			int a;
			cin >> a;
			p.push_back(a);
		}
		for(int i=0;i<n;i++)
		{
			if(p[i]==0)
			{
				c++;
			}
			else
			{
				v.push_back(c);
				c=0;
			}
		}
		v.push_back(c);
 
		vector<int> :: iterator it = max_element(v.begin(),v.end());
		cout << *it << endl;
	}
	return 0;
}

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NQo1CjEgMCAwIDEgMAo0CjAgMSAxIDEKMQowCjMKMSAxIDEKOQoxIDAgMCAwIDEgMCAwIDAgMQo=

5
5
1 0 0 1 0
4
0 1 1 1
1
0
3
1 1 1
9
1 0 0 0 1 0 0 0 1