#include <bits/stdc++.h>
using namespace std;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    string N;
    cin >> N;
    int len = N.size();
    int pos = (len - 1) % 3 + 1;
    for (int i = 1; i <= pos; ++i) cout << N[i - 1];
    while (pos < len){
        cout << ',';
        cout << N[pos] << N[pos + 1] << N[pos + 2];
        pos += 3;
    }
    return 0;
}