uses crt;
var f:text; t,n:longint;
a:array[1..10000000] of longint;
begin
clrscr;
assign(f,'SONGUYEN.TXT');reset(f);
t:=1;
while not(eoln(f)) do
begin
inc(n);
read(f,a[n]);
t:=t*a[n];
end;
close(f);
assign(f,'KETQUA.OUT');rewrite(f);
writeln(f,t);
close(f);
end.