//#include<iostream>
#include<vector>
#include<fstream>
#include<queue>
#include<unordered_map>
std::ifstream cin("nivele.in");
std::ofstream cout("nivele.out");
using namespace std;
unordered_map<int, int>mp;
void solve() {
	int n, ok = 0;
	cin >> n;
	vector<int>v(n + 1);
	for (int i = 1; i <= n; i++) cin >> v[i], mp[v[i]]++;
	for (int i = 1; i < n - 1; i++) ok = (mp[v[i]] > 1);
	if (v[n] != v[n - 1]) ok = 1;
	if (!ok) cout << "DA";
	else cout << "NU";
	cout << '\n';
}
int main() {
	int t;
	cin >> t;
	while (t--) solve();
	return 0;
}