// No.784 「,（カンマ）」
package main

import (
	"fmt"
)

func main() {
	const separator = ","
	const groupSize = 3

	var n string
	fmt.Scan(&n)

	reverse := func(s string) (r string) {
		for _, v := range s {
			r = string(v) + r
		}
		return
	}
	var ans string
	for i, v := range reverse(n) {
		if i > 0 && i%groupSize == 0 {
			ans = string(v) + separator + ans
		} else {
			ans = string(v) + ans
		}
	}
	fmt.Println(ans)
}