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

int main(){
    string str;
    cin >> str;
    int maxi = stoi(str);
    for(int i = 0 ; i < str.size() ; ++i){
        for(int j = i+1 ; j < str.size() ; ++j){
            char temp;
            temp = str[j];
            string t = str;
            t[j] = t[i];
            t[i] = temp;
            maxi = max(stoi(t) , maxi);
        }
    }
    cout << maxi << endl;
}