#include <fstream>
#include <stack>

using namespace std;

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

const int nmax= 50000;

int v[nmax+1];

int main(  ) {
    int t;
    fin>>t;
    for ( int cnt= 1; cnt<=t; ++cnt ) {
        int n, m= 0;
        fin>>n;
        for ( int i= 1; i<=n; ++i ) {
            fin>>v[++m];
            while ( m>=2 && v[m]==v[m-1] ) {
                --v[--m];
            }
        }

        if ( v[1]==1 && m==1 ) {
            fout<<"DA\n";
        } else {
            fout<<"NU\n";
        }
    }

    return 0;
}