#include<fstream>
#include<stack>

using namespace std;

const char iname[]="nivele.in";
const char oname[]="nivele.out";

ifstream f(iname);
ofstream g(oname);

int t,n,x;

int main()
{
    f>>t;
    while(t--)
    {
        f>>n;
        stack<int> S;
        while(n--)
        {
            f>>x;
            while(S.size()&&S.top()==x)
                S.pop(),--x;
            S.push(x);
        }
        if(S.size()==1&&S.top()==1)
            g<<"DA\n";
        else
            g<<"NU\n";
    }
}