#include <string>
#include <algorithm>
#include <iostream>
#include <vector>

using namespace std;
int main(){
    string str;
    vector<char> ch;
    while(getline(cin,str)){
        for (int i = 0; i < str.size(); ++i) {
            ch.push_back(str[i]);
        }
        sort(ch.begin(),ch.end());
        for (int i = 0; i < str.size(); ++i) {
            cout<<ch[i];
        }
    }
}