#define _USE_MATH_DEFINES

#include <iostream>		//cin, cout
#include <vector>		//vector
#include <algorithm>	//sort,min,max,count
#include <string>		//string,getline, to_string
#include <cstdlib>		//abs(int)
#include <utility>		//swap, pair
#include <deque>		//deque
#include <climits>		//INT_MAX
#include <bitset>		//bitset
#include <cmath>		//sqrt, ceil. M_PI, pow, sin
#include <ios>			//fixed
#include <iomanip>		//setprecision
#include <sstream>		//stringstream
#include <numeric>		//gcd, assumlate
#include <random>		//randam_device
#include <limits>		//numeric_limits

using namespace std;
constexpr long long int D_MOD = 1000000007;

int main() {

	string N;
	cin >> N;

	vector<int> A;
	for (unsigned int i = 0; i < N.length(); i++) {
		A.push_back(N[i] - '0');
	}

	sort(A.begin(), A.end(), greater<int>());

	for (unsigned int i = 0; i < A.size(); i++) {
		cout << A[i];
	}
	cout << endl;

	return 0;

}