use std::collections::HashMap;

fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let mut n: Vec<char> = n.trim().chars().collect();

    let mut max_right = vec!['0'; n.len()];
    let mut rpos = HashMap::new();
    for (i, &c) in n.iter().enumerate().rev() {
        if i == n.len() - 1 {
            max_right[i] = c;
        } else {
            max_right[i] = c.max(max_right[i + 1]);
        }
        rpos.entry(c).or_insert(i);
    }

    for i in 0..n.len() {
        if max_right[i] != n[i] {
            n.swap(i, rpos[&max_right[i]]);
            break;
        }
    }

    let n: String = n.iter().collect();

    println!("{}", n);
}