#include<fstream>
#define NMAX 50010

using namespace std;

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

int T, n, ns, a[NMAX], S[NMAX];

void Citeste()
{
    int i;

    f>>n;
    for (i=1; i<=n; ++i) f>>a[i];
}

void Solve()
{
    int i, val;

    ns=0;
    for (i=1; i<=n; ++i)
    {
        val=a[i];
        while (ns>0 && val==S[ns])
        {
            --ns; --val;
        }
        S[++ns]=val;
    }

    if (ns==1) g<<"DA\n";
    else g<<"NU\n";
}

int main()
{
    f>>T;

    while (T--)
    {
        Citeste();
        Solve();
    }

    f.close();
    g.close();
    return 0;
}