use std::io::*;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let mut s: Vec<char> = itr.next().unwrap().chars().collect();
    s.sort();
    let mut changed = false;
    for i in 0..s.len() - 1 {
        if s[i] != s[i + 1] && s[i] != '0' {
            s.swap(i, i + 1);
            changed = true;
            break;
        }
    }
    if changed {
        let s: String = s.into_iter().rev().collect();
        println!("{}", s);
    } else {
        println!("-1");
    }
}