def main():
    i = list(reversed(input()))
    n = ""
    x = len(i)
    for v in range(x):
        n += i[v]
        if (v + 1) % 3 == 0 and v + 1 != x:
            n += ","
    p = reversed(list(n))
    print("".join(p))

        
    

main()