#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
typedef long long int ll;

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