#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
#define int long long
using namespace std;
signed main() {
	string s; cin >> s;
	for (int i = 0; i < s.size(); i++) {
		if (i&&(s.size() - i) % 3 == 0)cout << ',';
		cout << s[i];
	}cout << endl;
}