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

int main() {
  ios::sync_with_stdio(false);

  string X;
  cin >> X;

  sort(X.begin(), X.end());
  reverse(X.begin(), X.end());

  for (int i = X.size() - 2; ~i; --i) {
    if (X[i] != X[i + 1]) {
      if (i == 0 && X[i + 1] == '0') continue;
      swap(X[i], X[i + 1]);
      cout << X << endl;
      return 0;
    }
  }

  cout << -1 << endl;

  return 0;
}