#include <iostream>
#include <bits/stdc++.h>
#include <time.h>
#include <sys/timeb.h>
#include <cstdio>
#include <sys/time.h>

using namespace std;
#define ll long long
#define uint unsigned int
#define ulong unsigned long long int

template<typename T> bool InRange(T t, T l, T r){ return l <= t && t < r; }

int main(){
	
	string s;
	cin >> s;
	
	vector<string> v;
	int N = s.length();
	for(int i=0;i<N;i+=3){
		int l = max((int)s.length() - i - 3,0);
		int len = min(3, max((int)s.length() - (i - 3) - 3,0) - l);
		v.push_back(s.substr(l,len));
	}
	
	reverse(v.begin(), v.end());
	string ans = "";
	for(int i=0;i<v.size();i++){
		if(i != 0) ans += ",";
		ans += v[i];
	}
	
	cout << ans << endl;
    return 0;
}