#include<bits/stdc++.h>
#define REP(i,n) for(int i=0,i##_len=(n);i<i##_len;++i)
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
#define All(x) (x).begin(),(x).end()
using namespace std;
using ll = long long;

int main(){
    string X;cin>>X;
    sort(All(X));
    string ans="-1";
    rep(i,1,X.size()){
        if(X[i-1]!=X[i]){
            swap(X[i-1],X[i]);
            reverse(All(X));
            if(X[0]!='0') ans=X;
            break;
        }
    }
    cout<<ans<<endl;
}