#include<fstream>
#include<vector>
#include<algorithm>
using namespace std;
ifstream fin("nivele.in");
ofstream fout("nivele.out");
int t,n,v[50001],i,ok;

int main(){
    fin>>t;
    for(;t>0;t--)
    {
        fin>>n;
        for(i=1;i<=n;i++)
        {
            fin>>v[++ok];
            if(ok>=2)
            {
                while(ok!=1)
                {
                    if(v[ok]==v[ok-1])
                    {
                        v[ok-1]=v[ok]-1;
                        ok--;
                    }
                    else
                        break;
                }
            }
        }
        if(ok==1&&v[ok]==1)
            fout<<"DA\n";
        else
            fout<<"NU\n";
    }
    fin.close();
    fout.close();
    return 0;
}