#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>


typedef long long int ll;
//#include<bits/stdc++.h>


using namespace std;



int main()
{

    int Q;
    Q = 1;
    //cin >> Q;
    
    
    while (Q--) {
        string p;
        cin >> p;
        reverse(p.begin(), p.end());
        string a;
        for (int i = 0; i < p.size(); i++) {
            if (i && i % 3 == 0)a.push_back(',');
            a.push_back(p[i]);
            
        }
        reverse(a.begin(), a.end());
            cout << a;


    }
    return 0; 
}