#include "bits/stdc++.h"
using namespace std;
using Graph = vector<vector<int>>;
typedef long long ll;
typedef pair<int, int> P;
#define rep(i,n) for (ll i = 0; i < (n); ++i)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
const long long mod = 1e9 + 7;

ll gcd(ll a, ll b) {
	return b ? gcd(b, a % b) : a;
}

ll lcm(ll a, ll b) {
	return a / gcd(a, b) * b;
}

int main() {
	string n;
	cin >> n;
	
	ll s=n.size();
	sort(rall(n));
	queue<char> q;
		
	rep(i, s) {
		q.push(n[i]);
	}

	string ans="";
	ll i=1;

	while (!q.empty()) {
		if (i != 1 && i % 4 == 0) {
			ans+=",";
		} else {
			ans+=q.front();
			q.pop();
		}
		i++;
	}
	reverse(all(ans));
	cout << ans << endl;
}