#include<bits/stdc++.h>
using namespace std;
 
#define int long long 
 
#define rep(i,n) for(int i=0;i<(n);i++)
#define pb push_back
#define eb emplace_back
#define all(v) (v).begin(),(v).end()
#define fi first
#define se second
typedef vector<int>vint;
typedef pair<int,int>pint;
typedef vector<pint>vpint;
 
template<typename A,typename B>inline void chmin(A &a,B b){if(a>b)a=b;}
template<typename A,typename B>inline void chmax(A &a,B b){if(a<b)a=b;}
 
template<class A,class B>
ostream& operator<<(ostream& ost,const pair<A,B>&p){
	ost<<"{"<<p.first<<","<<p.second<<"}";
	return ost;
}
 
template<class T>
ostream& operator<<(ostream& ost,const vector<T>&v){
	ost<<"{";
	for(int i=0;i<v.size();i++){
		if(i)ost<<",";
		ost<<v[i];
	}
	ost<<"}";
	return ost;
}


signed main(){
	string S;cin>>S;
	sort(all(S));reverse(all(S));

	int k=find(all(S),S.back())-S.begin();
	if(k==0||k==1&&S[k]=='0'){
		cout<<-1<<endl;
	}
	else{
		swap(S[k-1],S[k]);
		cout<<S<<endl;
	}
}