package main

import (
	"fmt"
	"strconv"
)

func main() {
	var n int
	fmt.Scan(&n)

	str := ""
	for i := 1; ; i++ {
		str = strconv.Itoa(n%10) + str
		n /= 10
		if n == 0 {
			break
		}
		if i%3 == 0 {
			str = "," + str
		}
	}
	fmt.Println(str)
}