//

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-1; i>=1; i--) {
				if ((length-i)%3==0) sb.insert(i,",");
		}
		
		System.out.println(sb);
		
	}
}