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

int main(){
    string s;
    cin >> s;
    bool same = true;
    int n = s.length();
    for (int i = 1; i < n; i++) {
        if (s[i]!= s[i-1]) {
            same = false;
            break;
        }
    }
    sort(s.begin(), s.end());
    reverse(s.begin(), s.end());
    swap(s[n-1], s[n-2]);
    cout << ((s[0] != '0' && !same) ? s : "-1") << endl;
    return 0;
}