NK05MNIM - Bốc sỏi
Tác giả: flashmt
Ngôn ngữ: Pascal
var t,j:longint;
n,i,k,l:byte;
a:array[1..100] of byte;
begin
readln(t);
for j:=1 to t do
begin
readln(n);
fillchar(a,sizeof(a),0);
k:=0;
for i:=1 to n do
begin
read(l);
if l=1 then inc(k)
else break;
end;
readln;
if k mod 2 = 0 then writeln(1)
else writeln(-1);
end;
end.