import random
import math

def isprime(num):
    """Returns True if the input is a prime number, False otherwise"""
    for i in range(2, int(math.sqrt(num)+1)):
        if num % i == 0:
            return False

    return True

def firstprimes(num):
    """Prints out the first num primes"""
    count = 0  # the number of primes we've printed out
    current = 2  # the current number we're checking
        
    while count < num:
        if isprime(current):
            print current
            count += 1 # same as count = count + 1
        
        current += 1 # same as current = current + 1

def number_guessing_game():
    """Play a number guessing game where the user tries to guess a number
    between 1 and MAX_GUESS and is given hints for lower and higher"""
    MAX_GUESS = 20
    
    number = random.randint(1, MAX_GUESS)
    
    finished = False
    
    while not finished:
        guess = int(raw_input("Guess a number between 1 and " + \
                              str(MAX_GUESS) + ": "))
        
        if guess == number:
            print "Good job!"
            finished = True
        elif guess < number:
            print "A bit higher"
        else:
            print "A bit lower"
            
# here's an alternate way of writing it that doesn't use a
# bool variable.  Either way is fine.
def number_guessing_game2():
    """Play a number guessing game where the user tries to guess a number
    between 1 and 20 and is given hints for lower and higher"""
    
    number = random.randint(1, 20)
    guess = 0 # start it out as some number that can't be right
    
    while guess != number:
        guess = int(raw_input("Guess a number: "))
        
        if guess < number:
            print "A bit higher"
        else:
            print "A bit lower"
    
    # when we exit the loop, we know the user's gotten it right
    print "Good job!"