program factor;
var
 i,res,n,re: Integer;
function factorial(n: word): word;
  begin
    if n<=1 then
     factorial:=1
    else
      factorial:=n*factorial(n-1);
  end;
begin
  writeln('Vvedite n');
  readln(n);
  factorial(n);
writeln('n!= ',factorial(n));
end.