Prime / non prime

num = input()
prime_sum = 0
non_prime_sum = 0
nonprime =  False

while True:
  if num == "stop":
    print(f"Sum of all prime numbers is: {prime_sum}")
    print(f"Sum of all non prime numbers is: {non_prime_sum}")
    break
  else:
    num = int(num)
    if num == 0 or num == 1:
      non_prime_sum += num
    if num > 1:
      if num in [2, 3, 5]:
        prime_sum += num
      else:
        for i in range(2, num // 2+1):
          if (num % i) == 0:
            nonprime = True
            break
        else:
          prime_sum += num
        if nonprime:
          non_prime_sum += num
    if num < 0:
      print(f"Number is negative.")
  num = input()
  prime = False
  nonprime = False