#!/mnt/c/Users/moiki/bash/env/bin/python
# N,M = map(int, input().split())
N = int(input())
strN = reversed(str(N))
ans = []
if len(str(N)) <= 3:
    print(str(N))
    exit(0)
for e,i in enumerate(strN):
    ans.append(i)
    if e % 3 == 2:
        ans.append(",")

if ans[-1] == ",":
    ans = ans[:-1]

print("".join(ans[::-1]))