#include <stdio.h>

int t,n,i,a[50002],b[50002],m,z;

int main()
{
	freopen("nivele.in","r",stdin);
	freopen("nivele.out","w",stdout);
	scanf("%d",&t);
	while (t)
	{
		--t;
		m=0;
		scanf("%d",&n);
		for (i=1; i<=n; ++i) 
		{
			scanf("%d",&a[i]);
			if (a[i]==b[m])
			{
				z=a[i]-1; --m;
				while (z==b[m]) 
				{
					--z;
					--m;
				}
				b[++m]=z;
			}
			else b[++m]=a[i];
		}
		if (m==1 && b[1]==1) printf("DA\n");
		else printf("NU\n");
	}
	return 0;
}