#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < n; ++i)
using ll = long long;
using namespace std;
const int INF = 1e9;

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

    int cnt = (3 - s.size() % 3) % 3;
    rep(i, s.size()) {
        ++cnt;
        cout << s[i];
        if (cnt == 3) {
            if (i != s.size() - 1)
                cout << ",";
            cnt = 0;
        }
    }
    cout << endl;

    return 0;
}