package main

import "fmt"

func main() {
	var s string
	fmt.Scan(&s)
	start := len(s) % 3
	for i := 0; i < len(s); i++ {
		if i != 0 && (i == start || (i-start)%3 == 0) {
			fmt.Print(string(","))
		}
		fmt.Print(string(s[i]))
	}
	fmt.Println()
}