#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pii pair<int, int>
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep3(i, l, n) for (int i = l; i < (n); ++i)
#define sz(v) (int)v.size()
#define inf (int)(1e9+7)
#define abs(x) (x >= 0 ? x : -(x))
#define ceil(a, b) a / b + !!(a % b)
template<typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { if (a > b) { a = b; return 1; } return 0; }
template<typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { if (a < b) { a = b; return 1; } return 0; }
template<typename T> T gcd(T a, T b) { if (b == 0) return a; return gcd(b, a % b); }




int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    
    string s;
    cin >> s;
    
    if (sz(s) < 6) {
        vector<int> v;
        do {
            v.eb(stoi(s));
        } while (next_permutation(all(s)));
        sort(all(v));
        // rep(i, sz(v)) cout << v[i] << " "; cout << endl;
        if (sz(v) == 1 || v[sz(v) - 1] == v[sz(v) - 2]) cout << -1 << endl;
        else cout << v[sz(v) - 2] << endl;
        return 0;
    }
    
    set<char> st;
    rep(i, sz(s)) st.insert(s[i]);
    if (sz(st) == 1) { cout << -1 << endl; return 0; }
    
    int c = 0;
    rep(i, sz(s)) if (s[i] != '0') c++;
    if (c <= 1) { cout << -1 << endl; return 0; }
    
    vector<int> v;
    rep(i, sz(s)) v.eb(s[i] - '0');
    sort(all(v), greater<int>());
    // rep(i, sz(v)) cout << v[i] << " "; cout << endl;
    
    int i = sz(s) - 1;
    while (i > 0 && v[i] == v[sz(s) - 1]) --i;
    
    string t;
    rep(j, i) t += v[j] + '0';
    
    t += v[sz(s) - 1] + '0';
    
    rep3(j, i, sz(s) - 1) t += v[j] + '0';
    
    i = 0;
    while (t[i] == '0') ++i;
    rep3(j, i, sz(t)) cout << t[j];
    cout << endl;
}