# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	n = ""
	S = input()
	for i in range(len(S)):
		n += S[-1 - i]
		if i % 3 == 2 and i != len(S) - 1:
			n += ","

	print(n[::-1])






if __name__ == '__main__':
	main()