// No.256 桁の数字を入れ替え (2)
// https://yukicoder.me/problems/no/256
//

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <iomanip>
using namespace std;

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    string N;
    cin >> N;

    vector<char> numbers;
    for (auto c: N) {
        numbers.push_back(c);
    }
    sort(numbers.begin(), numbers.end());
    reverse(numbers.begin(), numbers.end());

    for (auto c: numbers)
        cout << c;
    cout << endl;
}