var v:array[1..32000] of integer;
var f,g:text;
var p,t,i,n,x,j,y:integer;
begin
assign(f,'nivele.in'); reset(f);    assign(g,'nivele.out'); rewrite(g);
readln(f,t);
for p:=1 to t do
 begin
  read(f,n); i:=0;
  repeat
   i:=i+1;   read(f,v[i]);
  until eoln(f); readln(f);
  x:=n; y:=n-1; v[n+1]:=0;
  repeat
   if v[x]=v[y] then
    begin
     v[y]:=v[y]-1;
     for j:=x to n do
      v[j]:=v[j+1];
     n:=n-1; x:=n; y:=n-1;
    end          else
    begin
     x:=x-1; y:=y-1;
    end;
  until (n=1) or (y=-1);
  if (n=1) and (v[n]=1) then
   writeln(g,'da')          else
   writeln(g,'nu');
 end; close(f); close(g);
end.