#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <sstream>
#include <cstdio>
#include <cstdlib>
#include <cmath>


using namespace std;

int main(){
    int N;
    string S;
    cin >> S;

    vector<char> v;
    for(int i = 0; i< S.size(); i++)
        v.push_back(S[i]);


    auto it = max_element(v.begin(), v.end());
    swap(*it, v[0]);
    if(v.size() > 1){
        auto jt = max_element(v.begin()+1, v.end());
        swap(*jt, v[1]);
        if(it > jt) swap(it, jt);
        if(*it < *jt) swap(*it, *jt);
    }

    for(int i=0 ;i < v.size(); i++)
        cout << v[i];

    cout << endl;
    
    return 0;
}