use std::iter::FromIterator;

fn main() {
    let mut x = String::new();
    std::io::stdin().read_line(&mut x).expect("Input error");
    let mut xv = Vec::from_iter(x.trim().chars());

    xv.sort_by_key(|&x| std::cmp::Reverse(x));
    if (xv[0] == xv[xv.len() - 1]) || (xv[1] == '0') {
        println!("-1");
        return;
    }

    let prev_ch = xv[xv.len() - 1];
    for (i, xi) in xv.iter().enumerate().rev() {
        if *xi != prev_ch {
            xv.swap(i, i + 1);
            break;
        }
    }
    println!("{}", String::from_iter(xv.iter()));
}