#include "bits/stdc++.h"
using namespace std;

int main() {
	string N, X = "";
	cin >> N;
	for (int i = 0; i < N.size() - 1; i++) {
		X = N[N.size() - i - 1] + X;
		if (i % 3 == 2) X = ',' + X;
	}
	cout << N[0] << X << endl;
}