100 Days of Coding Day 2 2017

def get_integer(prompt):
    '''Prompts the user to enter an integer, and ensures the user enters an
    integer'''
    while True:
        try:
            num = int(input(prompt))
        except ValueError:
            print("That is not a number -- please try again without decimal"
                  "points")
            continue
        return num

'''Courtesy of Stack Overflow'''
def mod():
    '''Implements the challenge for 100 days of coding day 2'''
    a = get_integer("Please enter an integer:")
    b = get_integer("Please enter an integer:")
    c = get_integer("Please enter an integer:")

    number = 1
    while b:
        if b & 1:  # Uses the binary and
            number = number * a % c
        a >>= 1
        b = b * a % c
    return number

print(mod())