#pragma region Macros
// #pragma GCC target("avx2")
#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#include <atcoder/all>
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rrep(i, n) for (int i = (n - 1); i >= 0; i--)
#define ALL(v) v.begin(), v.end()
#define endl "\n"
#define popcount(bit) __builtin_popcount(bit)
#define popcountll(bit) __builtin_popcountll(bit)
#define pb push_back
#define eb emplace_back
using namespace std;
using namespace atcoder;
using P = pair<int, int>;
using PL = pair<long long, long long>;
using Graph = vector<vector<int>>;
typedef long long ll;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};
const int fx[8] = {0, 1, 1, 1, 0, -1, -1, -1};
const int fy[8] = {1, 1, 0, -1, -1, -1, 0, 1};
const ll INF = (1LL <<60);

int main() {
  string x;
  cin >> x;
  string tmp = x;
  int n = x.size();
  sort(ALL(tmp), greater{});
  rrep(i, n-1){
    if(tmp[i] != tmp[i+1]){
      swap(tmp[i], tmp[i + 1]);
      break;
    }
  }
  string tmp2 = string(x.size(), tmp[0]);
  if(tmp == tmp2 || tmp[0] == '0'){
    cout << -1 << endl;
  }else{
    cout << tmp << endl;
  }
}