#include <cstdio>
#define MAXN 50000
int stiv[MAXN];
int main(){
   FILE*fi,*fout;
   int i,n,t,ist,x;
   fi=fopen("nivele.in" ,"r");
   fout=fopen("nivele.out" ,"w");
   fscanf(fi,"%d " ,&t);
   while(t>0){
      t--;
      fscanf(fi,"%d " ,&n);
      ist=-1;
      for(i=1;i<=n;i++){
         fscanf(fi,"%d " ,&x);
         while(ist>=0&&stiv[ist]==x){
                ist--;
                x--;
          }
          stiv[++ist]=x;
      }
      if(ist==0&&stiv[ist]==1)
        fprintf(fout,"DA\n");
      else
        fprintf(fout,"NU\n");
   }
   fclose(fi);
   fclose(fout);
   return 0;
}