View Code of Problem 101

import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		while(scanner.hasNext()) {
			String s = scanner.next();
			String sss = s.replace(",", "");
			char[] ss = new char[sss.length()*2];
			int count =0;
			int k=0;
			for(int i=sss.length()-1;i>=0;i--) {
				if(count % 3==0 && count!=0) {
					ss[k++] = ',';
				}
				count++;
				ss[k++] = sss.charAt(i);
				
			}
			for(int j = k-1;j>=0;j--) {
				System.out.print(ss[j]);
			}
			System.out.println();
		}

		scanner.close();
}
}