#include <stdio.h>
#include <iostream.h>

int t, n, v[50005];

int main()
{
	freopen("nivele.in","r",stdin);
	freopen("nivele.out","w",stdout);
	scanf("%d",&t);
	int i, ok;

	while (t--)
	{

		scanf("%d",&n);
		for (i = 1; i <= n; i++)
		{
			scanf("%d",&v[i]);
			if (v[i] >= 50003){ ok = 4; break;}
			if (v[i] <= v[i-1] && i >= 2 ) ok = 3;
		}

		if(ok == 3)
		{
			if (ok != 4)
			{
				ok = 1;
				for (i = 2; i <= n; i++)
				if ( v[i] < v[i - 1] && v[i - 1] != v[i - 2]){ ok = 0; break;}
				if (ok) printf("DA\n");
				else printf("NU\n");
			}
		}
		else printf("NU\n");
	}
	return 0;
}