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

int main() {
    string n;
    cin >> n;
    int d = n.size(), r = (d - 1) % 3 + 1;
    cout << n.substr(0, r);
    for (int i = r; i < d; i += 3) {
        cout << "," << n.substr(r, 3);
    }
    cout << endl;
}