#include <bits/stdc++.h>
#define rep(i,n) for(int i=0; i<(n); i++)
#define rall(x) (x).rbegin(),(x).rend()
#define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end());
using namespace std;
typedef long long ll;


int main(){
	string s; cin>>s;
	int n=s.size();
	vector<int> v;
	rep(i,n){
		v.push_back(stoi(s.substr(i,1)));
	}
	sort(rall(v));
	if(v.size()==2&&v[1]==0){cout << "-1" << endl; return 0;}
	bool flg=false;
	while(!flg&&n>1){
		n--;
		if(v[n]!=v[n-1]) flg=true;
	}
	if(flg){
		int t=v[n-1];
		v[n-1]=v[n];
		v[n]=t;
		for(auto x:v) cout << x;
		cout << endl;
	} else { cout << "-1" << endl;
	}
}