number = input()

numberlist = str(number)[::-1]

qianfenwei = []

for i in range(len(numberlist)):
    if i % 3 == 0 and i != 0:
        qianfenwei.append(',')
    qianfenwei.append(numberlist[i])

qianfenwei = qianfenwei[::-1]

for i in range(len(qianfenwei)):
    print(qianfenwei[i], end='')