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

int main() {
    string s;
    cin >> s;
    string ans;
    reverse(s.begin(), s.end());
    for (int i = 0; i < s.size(); i++) {
        if (i % 3 == 0) ans = "," + ans;
        ans = s[i] + ans;
    }
    cout << ans << endl;
    return 0;
}