#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<long long,long long> pll;
#define pb push_back
#define mp make_pair
#define rep(i,n) for(int i=0;i<(n);++i)
constexpr int mod=1000000007;
constexpr int mod1=998244353;
vector<int> dx={0,1,0,-1},dy={-1,0,1,0};
bool inside(int y,int x,int h,int w){
	if(y<h && y>=0 && x<w && x>=0) return true;
	return false;
}





int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	string s;cin >> s;
	sort(s.rbegin(),s.rend());
	bool ok = false;
	for(int i = s.size() - 1; i >= 0; i--){
		if(s.at(i) != s.at(s.size() - 1)){
			if(i == 0 && s.at(s.size() - 1) == '0') break;
			swap(s.at(i), s.at(s.size() - 1));
			ok = true;
			break;
		}
	}
	if(ok) cout << s << endl;
	else cout << -1 << endl;
}