#include <bits/stdc++.h>

#define ll long long
#define ld long double
#define rep(i,a,b) for (int i = a; i < b; i++)
#define irep(i,a,b) for (int i = a; i > b; i--)
#define print(n) cout << n << endl
#define rup(a,b) (a+b-1)/b

using namespace std;

int main(){
    cout << fixed << setprecision(15);
    
    int N;
    cin >> N;
    int ans = 0;
    string s = to_string(N);
    rep(i,0,s.size()){
        rep(j,0,s.size()){
            string a = to_string(N);
            swap(a[i],a[j]);
            ans = max(ans,stoi(a));
        }
    }
    
    print(ans);
    //system("pause");
    return 0;
}