#include <fstream>
using namespace std;

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

const int MAXN = 50003;

int stiva[MAXN];
int l_stiva;

void test()
{
    int n;
    in >> n;
    l_stiva = 1;
    in >> stiva[1];
    for (int i = 2;i <= n;++i)
    {
        int nr;
        in >> nr;
        while(stiva[l_stiva] == nr)
        {
            --l_stiva;
            --nr;
        }
        stiva[++l_stiva] = nr;
    }
    if(l_stiva == 1 && stiva[1] == 1)
        out << "DA\n";
    else out << "NU\n";
}

int main()
{
    int nrt;
    in >> nrt;
    while (nrt > 0)
    {
        test();
        nrt--;
    }
    return 0;
}