// this is wrong i know
#include <iostream>
#include <map>
#include <vector>
using namespace std;
int main()
{
	int t;
	map<int, int> indecies;
	cin >> t;
	while (t--)
	{
		int n;
		cin >> n;
		int zeroI = -1;
		vector<int> nums(n, 0);
		vector<vector<int>> mex(n, vector<int>(n));
		int sum = 0;
		for (int i = 0; i < n; i++)
		{
			cin >> nums[i];
			indecies[nums[i]] = i;
		}
		// traverse around zero index
		cout << sum << endl;
	}
}