#include <fstream>

using namespace std;

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

const int max_size = 5e4 + 1;

int stiva[max_size];

void solve ()
{
    int n, vf = 0;
    stiva[1] = 0;
    in >> n;
    while (n--)
    {
        int x;
        in >> x;
        stiva[++vf] = x;
        while (vf > 1 && stiva[vf] == stiva[vf - 1])
        {
            stiva[--vf]--;
        }
    }
    if (vf == 1 && stiva[vf] == 1)
    {
        out << "DA";
    }
    else
    {
        out << "NU";
    }
    out << '\n';
}

int main ()
{
    int t;
    in >> t;
    while (t--)
    {
        solve();
    }
    in.close();
    out.close();
    return 0;
}