#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
  #include "settings/debug.cpp"
  #define _GLIBCXX_DEBUG
#else
  #define Debug(...) void(0)
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

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