n = input()
l = list(n)
l2 = []
if len(n)<3:
print(n)
else:
l.reverse()
for index,value in enumerate(l,1):
l2.append(value)
if index % 3 == 0 and index != len(l):
l2.append(',')
l2.reverse()
print(''.join(l2))
import math
N = int(input())
arr =list(str(N))
tem = -3
count =math.ceil(len(arr)/3)
for i in range(count-1):
arr.insert(tem,',')
tem =tem-4
print("".join(arr))