#include <iostream>
#include <fstream>
#include <algorithm>
#include <stack>

///#include <tryhardmode>
///#include <GODMODE::ON>
///suntem la alte nivele :))

using namespace std;

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

const int NMAX=5e4+5;
stack<int>stiva;

int main()
{
    int n,i,j,t,x;
    fin>>t;
    while(t--)
    {
        fin>>n;
        for(i=1;i<=n;i++)
        {
            fin>>x;
            while(!stiva.empty() && stiva.top()==x)
            {
                stiva.pop();
                x--;
            }
            stiva.push(x);
        }
        if(stiva.size()==1 && stiva.top()==1)
            fout<<"DA\n";
        else
            fout<<"NU\n";
        while(!stiva.empty())
            stiva.pop();
    }
    return 0;
}