#include <bits/stdc++.h>
#define rep(i, n) for(long long i = 0; i < n; i++)
#define ALL(v) (v).begin(), (v).end()
using namespace std;

using lint = long long;

int main() {
    string s;
    cin >> s;
    int n = s.size();
    lint ans = 0;
    rep(i, n) {
        rep(j, n) {
            string t = s;
            swap(t[i], t[j]);
            ans = max(ans, stoll(t));
        }
    }
    cout << ans << endl;
}