#include <cstdio>
#define DIM 50002
int T,nf,v,i,x,j;
int S[DIM];

int main(){
    FILE *fin = fopen("nivele.in","r");
    FILE *fout = fopen("nivele.out","w");
    fscanf(fin,"%d",&T);
    for (i=1;i<=T;i++) {
        fscanf(fin,"%d",&nf);
        fscanf(fin,"%d",&S[1]);
        v = 1;
        for (j=2;j<=nf;j++) {
            fscanf(fin,"%d",&x);
            while(S[v] == x) {
                v--;
                x--;
            }
            S[++v] = x;
        }
        if ((v==1)&&(S[1]==1)) {
            fprintf(fout,"DA\n");
        } else {
            fprintf(fout,"NU\n");
        }
    }

    return 0;
}