#include <iostream>

#include <vector>

#include <fstream>

#include <algorithm>

using namespace std;

int v[50001],p,T,t,i,n;

int main()

{
	ifstream fin ("nivele.in");
	ofstream fout ("nivele.out");

cin>>T;
for(t=1;t<=T;t++)
     {
     	cin>>n;
     	p=0;
     	for(i=1;i<=n;i++)
     	   {
        		p++;
        		cin>>v[p];
        		while ( (v[p-1]==v[p]) && p>1)
        		      {
              		p--;
              		v[p]--;	
              		}
        	}
        	if(p==1&&v[p]==1)
        	cout<<"DA\n";
        	else
           cout<<"NU\n";
     }


}