import math

N = input()
l = list(N)
count_d = math.ceil(len(N) / 3) - 1


l.reverse()
for i in range(count_d):
    ins = (i + 1) * 3 + i
    l.insert(ins, ",")
l.reverse()
ans = ""
for l_i in l:
    ans += l_i
print(ans)