Sum Prime Non Prime

command = input()
sum_prime = 0
sum_nonprime = 0

while command != "stop":
    number = int(command)
    counter = 0
    if number < 0:
        print("Number is negative.")
    else:
        for i in range(1, number+1):
            if number % i == 0:
                counter +=1
        if counter == 2:
            sum_prime += number
        else:
            sum_nonprime += number
    command = input()
print(f"Sum of all prime numbers is: {sum_prime}")
print(f"Sum of all non prime numbers is: {sum_nonprime}")