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())