#include <iostream>

#include <unordered_set>

#include <vector>

using namespace std;

int main()

{

	ios_base::sync_with_stdio(false);

	cin.tie(nullptr);

	cout.tie(nullptr);

	int n, k, temp;

	size_t total;

	unordered_set<int> snowflake;

	vector<int> cpy;

	cin >> n;

	while (n--) {

		total = 0;

		cin >> k;

		while (k--) {

			cin >> temp;

			if (snowflake.count(temp)) total = max(total, snowflake.size());

			while (snowflake.count(temp)) snowflake.erase(*cpy.begin()), cpy.erase(cpy.begin());

			cpy.emplace_back(temp);

			snowflake.emplace(temp);

		}

		total = max(total, snowflake.size());

		cout << total << "\n";

		snowflake.clear();

		cpy.clear();

	}

	return 0;

}