//

import java.util.*;

class Main {
	static Scanner sc = new Scanner(System.in);
	public static void main(String[] args) {

		StringBuilder sb = new StringBuilder(sc.next());
		int length = sb.length();
		for (int i=length; i>=0; i--) {
			if (length-i!=0 && i!=0) {
				if ((length-i)%3==0) sb.insert(i,",");
			}

		}
		System.out.println(sb);
	}
}