#include <fstream>
#define VAL 50005

using namespace std;

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

int T, i, N;
int top, nr, j;
int v[VAL];

int main()
{
    fin >> T;
    for (i=1; i<=T; i++)
    {
        fin >> N;
        top=0;
        for (j=1; j<=N; j++)
        {
            fin >> nr;
            if (nr==v[top])
            {
                v[top]=nr-1;
                while (v[top]==v[top-1])
                  v[--top]--;
            }
            else
              v[++top]=nr;
        }
        if (top==1 && v[top]==1)
          fout << "DA\n";
        else
          fout << "NU\n";
    }
    fin.close();
    fout.close();
    return 0;
}