#include <bits/stdc++.h>
using namespace std;

void solve() {
	int n; cin >> n;
	vector<int> a(n);
	for (int i = 0; i < n; i ++) cin >> a[i];
	if (a[0] != a[n - 1]) {
		cout << "Yes\n";
	} else {
		for (int i = 1; i + 1 < n; i ++) {
			if (a[i] == a[i + 1] && a[i] != a[0]) {
				cout << "Yes\n";
				return;
			}
		}
		int cnt = 0;
		for (int i = 0; i < n; i ++) if (a[i] != a[0]) ++ cnt;
		if (cnt >= 4) cout << "Yes\n";
		else cout << "No\n";
	}
}

int main() {
	ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
	int tt; cin >> tt;
	while (tt --) solve();
	return 0;
}