#include <fstream>
using namespace std;

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

int n,i,j,t,u,v[50000];

int main(){
    fin>>t;
    for(;t;t--){
        fin>>n;
        u=0;
        for(i=1;i<=n;i++){
            fin>>v[++u];
        }

        while(u>1 && v[u]==v[u-1]){
            v[--u]=v[u]-1;
        }

        if(u==1){
            fout<<"DA\n";
        }else{
            fout<<"NU\n";
        }
    }

    return 0;
}