import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder(br.readLine());
        int l = sb.length();
        for(int i=l-1; i>=0; i--){
            if ((l-i)%3==0) sb.insert(i,",");
        }
        System.out.println(sb);
    }
}