var v:array[0..50100] of longint;
    n,i,j,t,k,nr:longint;

begin
assign(input,'nivele.in');reset(input);
assign(output,'nivele.out');rewrite(output);
readln(t);
for j:=1 to t do
        begin
        read(n);
        k:=0;
        for i:=1 to n do
                begin
                read(nr);
                if nr=v[k] then
                        v[k]:=nr-1
                else
                        begin
                        inc(k);
                        v[k]:=nr;
                        end;
                while v[k]=v[k-1] do
                        begin
                        dec(k);
                        v[k]:=v[k]-1;
                        end;
                end;
        if (k=1)and(v[1]=1) then
                writeln('DA')
        else
                writeln('NU');
        end;
close(input);close(output);
end.