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