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

void no_927(void) {
    string x;
    cin >> x;
    sort(x.begin(), x.end());
    reverse(x.begin(), x.end());

    int x_size = (int)x.size();
    bool is_swap = false;
    for (int i = x_size - 2; i >= 0; i--) {
        if (x[x_size - 1] != x[i]) {
            swap(x[i], x[x_size - 1]);
            is_swap = true;
            break;
        }
    }
    if (!is_swap) {
        cout << "-1" << endl;
        return;
    }

    if (x[0] == '0') {
        cout << "-1" << endl;
        return;
    }
    cout << x << endl;
}

int main(void) {
    no_927();
    return 0;
}