>>> def isPrime(n):
	for x in range(2, n):
		if n % x == 0:
			return False
	else:
		# loop fell through without finding a factor
		return True

def isPrime(n):
	stack.push(1)
	stack.push(n)
	stack.pick()
	stack.pick()
	while stack.pop() - stack.pop():
		stack.swap()
		stack.inc()
		stack.swap()
		stack.pick()
		stack.pick()
		stack.push(divmod(stack.pop(),stack.pop()))
		stack.swap()
		stack.discard()
		if stack.pop() == 0:
			stack.push(0)
			print(stack.pop())
			stack.duplicate()
			stack.duplicate()
			stack.duplicate()
	if stack.pop() - stack.pop():
		# loop fell through without finding a factor
		stack.push(1)
		print(stack.pop())

stack.push(1)
stack.swap()
if stack.pop():
	stack.dec()
#The stack now becomes 0 if it started not zero, and vice versa.