#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const double PI = acos(-1);
const ll MOD = 1000000007;

int main() {
  string X; cin >> X;
  int N = X.size();
  
  sort(X.begin(),X.end());
  reverse(X.begin(),X.end());
  
  bool can = false;
  for (int i = 1; i < N; i++) {
    if (X[N-i-1] != X[N-i]) {
      can = true;
      swap(X[N-i],X[N-i-1]);
      break;
    }
  }
  
  if (X[0] == '0') can = false;
  
  if (can) cout << X << endl;
  else cout << -1 << endl; 
}