def fib_seq(num):
    a = 1
    b = 0
    seq = []
    for i in range(0, num):
        seq.append(str(a + b))
        a = int(seq[i])
        if i - 1 < 0:
            b = 0
        else:
            b = int(seq[i-1])
    seq = ', '.join(seq)
    return seq


def main():
    print "To what nth term would you like to see the Fibonacci Sequence?"
    while True:
        nth = raw_input("> ")
        if not nth.isdigit():
            print "Integers only"
        else:
            break
    print fib_seq(int(nth))

if __name__ == '__main__':
    main()
