fn main() {
    proconio::input! {
        s: String,
    }
    let mut c = s.chars().collect::<Vec<_>>();
    for i in 0..c.len() {
        let max = c
            .iter()
            .copied()
            .enumerate()
            .filter(|&(_, x)| x > c[i])
            .max_by_key(|x| x.1);
        if let Some((j, _)) = max {
            c.swap(i, j);
            break;
        }
    }
    println!("{}", c.iter().collect::<String>());
}