#include <fstream>
#include <vector>
#define MAXN 50005
using namespace std;
ifstream f("nivele.in");
ofstream g("nivele.out");

int t,i,n,x;
vector<int> v;

int main()
{
    f>>t;
    while(t--){
        f>>n;
        v.clear();
        for(i=1;i<=n;i++){
            f>>x;
            while(v.size()&&v.back()==x){
                x--;
                v.pop_back();}
            v.push_back(x);}
        if(v.size()==1&&v[0]==1)
            g<<"DA\n";
        else
            g<<"NU\n";}
    f.close();
    g.close();
    return 0;
}