#include <cstdio>

const int maxn = 50001;

FILE *in = fopen("nivele.in","r"), *out = fopen("nivele.out","w");

int t;
int n, k;
int a[maxn];
int st[maxn];

int main()
{
    fscanf(in, "%d", &t);

    while ( t-- )
    {
        fscanf(in, "%d", &n);

        for ( int i = 1; i <= n; ++i )
            fscanf(in, "%d", &a[i]);

        st[++k] = a[1];
        for ( int i = 2; i <= n; ++i )
            if ( a[i] != st[k] )
                st[++k] = a[i];
            else
                --a[i], --st[--k];

        if ( k == 1 && st[1] == 1 )
            fprintf(out, "DA\n");
        else
            fprintf(out, "NU\n");
    }


	return 0;
}