#include <fstream>
 
using namespace std;
 
ifstream cin("nivele.in");
ofstream cout("nivele.out");

const char *mm[2] = {"NU","DA"};
const int nmax = int(5e4) + 2;
int T, N;
int st[nmax], K;

int main()
{
	int T;
	for(cin>>T;T;T--) {
		cin>>N;
		int lvl;
		K = 0;
		for(int i = 1;i <= N;i++) {
			cin>>lvl;
			st[++K] = lvl;
			while(K > 1 && st[K - 1] == st[K]) {
				st[K - 1]--;
				K--;
			}
			
		}
		cout<<mm[K == 1 && st[1] == 1]<<"\n";	
	}
    return 0;
}