def ans(n):
    an = []
    len_n = len(n)
    for i,ni in enumerate(reversed(n)):
        an.insert(0,ni)
        if i + 1 < len_n  and (i + 1) % 3 == 0:
            an.insert(0,",")
    return  "".join(an)


if __name__ == '__main__':
    n = list(input())
    print(ans(n))