#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" << endl;
        return ;
    }
    for (int i = 0; i < n-1; i++){
        if (a[0] != a[i] && a[i] == a[i+1]){
            cout << "Yes" << endl;
            return ;
        }
    }
    int cnt = 0;
    for (int i = 0; i < n; i++){
        if (a[0] != a[i]) cnt++;
    }
    cout << (cnt >= 4 ? "Yes" : "No") << endl;
}

int main(){
    int t; cin >> t;
    while (t--){
        solve();
    }
}