#include<iostream>
#include<string>
#include <vector>
#include<queue>
#include<map>
#include<algorithm>
#include<iomanip>
#include<cmath>
#include<bitset>
using namespace std;
using vi = vector<int>;
using vii = vector<vi>;
using vs = vector<string>;
using pii = pair<int, int>;
#define rep(i,n) for(int i=0;i<n;i++)
#define rep2(i,m,n) for(int i=m;i<n;i++)
#define vsort(v) sort(v.begin(), v.end())
#define rv(v) reverse(v.begin(), v.end())
#define ll long long
#define PI 3.141592653589793
using vll = vector<ll>;
using Graph = vii;
const ll MOD = 998244353;

int main() {
	string x, t;
	cin >> x;
	t = x;
	vsort(x);
	vsort(t);
	ll n = t.size();
	if (t[0] == t[n - 1] || t[n - 1] == '0') {
		cout << -1 << endl;
		return 0;
	}
	t[0] = x[1];
	t[1] = x[0];
	ll ans = 0;
	rep(i, n) {
		int k = t[i] - '0';
		ans += k * pow(10.0, i);
	}
	cout << ans << endl;
	return 0;
}