n = input()
l = len(n)
judge = [False, False, True]
jl = 0

ans = []
a = ""

for i in range(l):
	if jl % 3 == 2:
		ans.append("," + n[l-i-1])
	else:
		ans.append(n[l-i-1])

ans.reverse()

for i in ans:
	a += i

print(a)