#include <bits/stdc++.h>
#include <iostream>
#include <string>
#include <stdlib.h>
using namespace std;

int main() {
string s;
cin>>s;
vector<int> a(s.length());
vector<int> b(s.length());

for (int i = 0; i < s.length(); ++i) {
	b[i]=a[i]=s[i]-48;
}
sort(b.begin(),b.end(),greater<int>());
int counter=0;
for (int i = 0; i < s.length(); ++i) {
	cout<<b[i];
}
cout<<endl;


}