program nivele;
var f,g:text;
    n,k,i,j,l,x:longint;
    v:array[1..50000] of longint;
procedure rec(var x,l:longint);
    begin
      if v[l-1]=x then
         begin v[l-1]:=v[l]-1; l:=l-1; if l>1 then rec(v[l],l); end;
    end;
begin
assign(f,'nivele.in'); reset(f); readln(f,k);
assign(g,'nivele.out'); rewrite(g);
for i:=1 to k do
   begin
      read(f,n);
      l:=1; read(f,v[1]);
      for j:=2 to n do
         begin
           read(f,x);
           inc(l); v[l]:=x;
           rec(x,l);
         end;
      if (l=1)and(v[1]=1) then writeln(g,'DA')
         else writeln(g,'NU');
      readln(f);
   end;
close(g); close(f);
end.