#include <cstdio>
using namespace std;
const int nmax=50004;
int p;
int v[nmax];
int n;
int main()
{
    freopen ("nivele.in","r",stdin);
    freopen ("nivele.out","w",stdout);
    int t;
    scanf("%d",&t);
    for(;t>0;--t)
    {
        scanf("%d",&n);
        scanf("%d",&v[1]);
        p=1;
        for(int i=2;i<=n;i++)
        {
            int val;
            scanf("%d",&val);
            while(p>0&&val==v[p])
            {
                --val;
                --p;
            }
            v[++p]=val;
        }
        if(p!=1||v[1]!=1) printf("NU\n");
        else printf("DA\n");
    }
}