#include<bits/stdc++.h> using namespace std; using ll=long long ; const int N =1e3+5; vector <ll> a; ll b[N]; int main(){ string n; cin>>n; ll k=n.size(); ll i=k-2; while(i>=0&&n[i]<=n[i+1]){ i--; } if(i==-1) { cout<<-1<<'\n'; return 0; } ll j=k-1; while(j>i&&n[j]>=n[i]){ j--; } swap(n[i],n[j]); reverse(n.begin()+i+1,n.end()); if(n[0]=='0'){ cout<<-1<<'\n'; } else cout<<n; }