lets STUDY

program fakto;
uses wincrt;
var  i,n,f :integer;
begin
f:=1;
readln(n);
for i:=n downto 2 do
begin
write (i,'x');
f:=i*f;
end;
if n<0 then write ('tidak terdefinisikan') else
write (1,'=',f);
end.