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

int main() {
    string s;
    cin >> s;
    int n = s.size();
    sort(s.rbegin(), s.rend());
    for (int i = n - 2; i >= 0; i--) {
        if (s.at(i) != s.at(i + 1)) {
            swap(s.at(i), s.at(i + 1));
            break;
        }
        if (i == 0) {
            cout << -1 << endl;
            return 0;
        }
    }
    if (s.at(0) == '0') {
        cout << -1 << endl;
        return 0;
    }
    cout << s << endl;
}