n = input()
m = len(n)
l = m % 3
ans = ""

if m > 3:
    if l != 0:
        ans += n[:l] + ","
    
    while l < m-3:
        ans += n[l:l+3] + ","
        l += 3
    ans += n[-3:]
else:
    ans = n

print(ans)