# 添加逗号
exm = input()
exm = [ch for ch in exm]
# print(exm)
ji = 1
biao = len(exm) - 1
while biao > 0:
    #print(biao)
    if ji == 3:
        # print('进入'+str(biao))
        exm.insert(biao, ",")
        # print(exm)
        ji = 1
        biao = biao - 1
    else:
        biao = biao - 1
        ji = ji + 1
exm = "".join(exm)
print(exm)