def printNum (lst, i):
    for x in range(1, len(lst)+1):
        if (x-1) % 3 == i and (x-1) != 0:
            print(",{}".format(lst[x-1]), end="")
        else:
            print(lst[x-1], end="")
    print("")
if __name__ == '__main__':
    n = list(input())
    l = len(n)
    if l <= 3:
        printNum(n, 0)
    else:
        printNum(n, l % 3)