start
int factorial
int i=1, ifact=1

print "Enter a number: "
input factorial

int tempfact=factorial
int factstore=factorial-1

if (factorial==0)
	print "invalid"
elseif (factorial<0)
	print "Out of range"
else
	while (i<=factorial)
		int tempnew=tempfact
		ifact=1
		while	(ifact<factstore)
			tempfact=tempfact+tempnew
			ifact++
		endwhile
		factstore--
		i++
	endwhile
	print tempfact

end