#include <iostream>

using namespace std;

int main() {
    string s;
    cin >> s;

    string ret;
    for (int i = 1; i <= s.size(); i++) {
        ret = s[s.size() - i] + ret;
        if (i % 3 == 0 && i != s.size())ret = "," + ret;
    }
    cout << ret << endl;
    return 0;
}