#include <bits/stdc++.h>
using namespace std;

int main() {
  int X;
  cin >> X;
  int N = to_string(X).size();
  vector<int> V(N);
  for (int i = 0; i < N; i++) V.at(i) = X % 10, X /= 10;
  set<int> S;
  do {
    if (!V.at(0)) continue;
    int tmp = 0, dig = 1;
    for (int i = N - 1; i >= 0; i--) tmp += V.at(i) * dig, dig *= 10;
    S.insert(tmp);
  } while (next_permutation(V.begin(), V.end()));
  cout << ((S.size() < 2) ? -1 : *next(rbegin(S))) << "\n";
}