# This tests whether numbers supplied by the user are prime.

def divides(a, b):
    # returns True if a divides evenly into b
    if b % a == 0:
        return True
    else:
        return False
    
def isPrime(x):
    # returns True if x is prime, False otherwise
    for factor in range(2, x):
        if divides(factor, x):
            return False
    else:
        return True

def main():
    done = False
    while not done:
        num = input( "Enter a number, or 0 to exit: " )
        if num == 0:
            done = True
        else:
            if isPrime(num):
                print "That number is prime"
            else:
                print "Not prime"
            
main()