#include <fstream>
using namespace std;
ifstream fin("nivele.in");
ofstream fout("nivele.out");
int n,t,x,stiva[50100],k;
int main(){
    fin>>t;
    for(;t--;){
        fin>>n;
        k=0;
        for(int i=1;i<=n;i++){
            k++;
            fin>>stiva[k];
            while(k>1&&stiva[k]==stiva[k-1]){
                k--;
                stiva[k]--;
            }
        }
        if(k==1&&stiva[k]==1)
            fout<<"DA\n";
        else
            fout<<"NU\n";
    }
    return 0;
}