program h247;
uses crt;
var i, n, tich: integer;
a:array[1..500]of integer;
begin
write('Nhap n '); readln(n);
tich:=1;
for i:=1 to n do
begin
write('Nhap a[',i,'] '); readln(a[i]);
if a[i] mod 2=0 then tich:=tich*i;
end;
write('Tich cac so chan la ',tich);
end.