#include <cstdio>
int t;
int stack[50002];
int dim_stack;

void iofile(void){
	freopen("nivele.in","rt",stdin);
	freopen("nivele.out","wt",stdout);
	scanf("%d",&t);
}

void prel_test(void){
	int i,x,n;
	dim_stack=0;
	scanf("%d",&n);
	for (i=1;i<=n;i++){
		scanf("%d",&x);
		stack[++dim_stack]=x;
		while (dim_stack>1 && stack[dim_stack]==stack[dim_stack-1]){stack[--dim_stack]--;}
	}
	if (dim_stack!=1 || stack[dim_stack]!=1){
		printf("NU\n");} else {printf("DA\n");}
}

void solve(void){
	for (int i=1;i<=t;i++){
		prel_test();
	}
	fclose(stdin);
	fclose(stdout);
}

int main(void){
	iofile();
	solve();
	return 0;
}