#include <iostream>
#include <vector>
#include <algorithm>
#include <iomanip>
#include <string>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <tuple>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cassert>
#include <cstdint>
#include <numeric>
#include <bitset>
#include <functional>

using namespace std;

using ll =  long long;
using Pll = pair<ll, ll>;
using Pii = pair<int, int>;

constexpr ll MOD = 1000000007;
constexpr long double EPS = 1e-10;
constexpr int dyx[4][2] = {
    { 0, 1}, {-1, 0}, {0,-1}, {1, 0}
};

int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    string s;
    cin >> s;
    int n = s.length();
    vector<int> v(n);
    for(int i=0;i<n;++i){
        v[i] = s[i] - '0';
    }
    sort(v.rbegin(), v.rend());

    bool swaped = false;
    int i = n-1;
    while(i > 0 && v[i] == 0) --i;
    if(i == 0) {
        cout << -1 << endl;
        return 0;
    }
    for(;i>0;--i) {
        if(v[i-1] > v[i]) {
            swap(v[i-1], v[i]);
            swaped = true;
            break;
        }
    }
    if(!swaped) {
        cout << -1 << endl;
    } else {
        for(int i=0;i<n;++i) cout << v[i];
        cout << endl;
    }
}