#include <string>
#include <vector>
#include <iostream>
#include <algorithm>
#include <functional>
using namespace std;

int keta(long long x){
	int sum=0;
	while(x){
		sum++;	
		x/=10;
	}
	return sum;
}

int main() {
	string x;
	cin >> x;
	sort(x.begin(),x.end());
	reverse(x.begin(),x.end());
	vector<string> s;
	do{
		s.push_back(x);
		if(s.size()>=2)break;
	}while(prev_permutation(x.begin(),x.end()));
	
	if(s.size()==1){
		cout << -1 << endl;
		return 0;
	}
	
	if(s[1][0]=='0'){
		cout << -1 << endl;
		return 0;
	}
	
	cout << s[1] << endl;
	
	return 0;
}