var
a, b, c: integer;
j, k, rez1, rez2, rez3, n, i: integer;
begin
readln(n);
i := 1;
j := 1;
k := 1;
repeat
readln(b);
if b < 0 then
rez2 := i;
i := i + 1;
until (b < 0) or (i = 40);
repeat
readln(a);
if a < 0 then
rez3 := j;
i := i + 1;
until (a < 0) or (j = 30);
repeat
readln(c);
if c < 0 then
rez1 := k;
k := k + 1;
until (c < 0) or (k = n);
if (rez1 < rez2) and (rez1 < rez3) then
writeln('da')
else
writeln('net');
end.