#include <iostream>
#include <vector>
using namespace std;

int main() {
    string N;
    cin >> N;
    int n = N.size() / 3;
    int na = N.size() % 3;
    vector<string> vc;
    if (na != 0) vc.push_back(N.substr(0, na));
    for (int i = na; i < N.size(); i += 3) {
        vc.push_back(N.substr(i, 3));
    }
    if (vc.size() == 1) cout << N << endl;
    else {
        for (int i = 0; i < vc.size(); i++) {
            cout << vc.at(i);
            if (i != vc.size() - 1) cout << ",";
        }
        cout << endl;
    }
    return 0;
}