import math
import sys
from operator import itemgetter
input = sys.stdin.readline().rstrip

# a = int(input())
# a, b = map(int, input().split())
# D = list(map(int, input().split()))
# H = [int(input()) for _ in range(L)]
# DD = [[0 for j in range(100)] for i in range(200)]

# if __name__ == '__main__':

s_in = str(input())
s_out = ""

i = 0
while (i < len(s_in)):
	s_out += s_in[len(s_in) - i - 1]
	i += 1
	if (i % 3 == 0) and (i < len(s_in)):
		s_out += ","

print(s_out[::-1])