#![allow(unused_imports)]
#![allow(non_snake_case)]
use std::collections::HashMap;

#[allow(unused_macros)]
macro_rules! read {
    ([$t:ty] ; $n:expr) =>
        ((0..$n).map(|_| read!([$t])).collect::<Vec<_>>());
    ($($t:ty),+ ; $n:expr) =>
        ((0..$n).map(|_| read!($($t),+)).collect::<Vec<_>>());
    ([$t:ty]) =>
        (rl().split_whitespace().map(|w| w.parse().unwrap()).collect::<Vec<$t>>());
    ($t:ty) =>
        (rl().parse::<$t>().unwrap());
    ($($t:ty),*) => {{
        let buf = rl();
        let mut w = buf.split_whitespace();
        ($(w.next().unwrap().parse::<$t>().unwrap()),*)
    }};
}

#[allow(dead_code)]
fn rl() -> String {
    let mut buf = String::new();
    std::io::stdin().read_line(&mut buf).unwrap();
    buf.trim_end().to_owned()
}

trait IteratorExt: Iterator + Sized {
    fn vec(self) -> Vec<Self::Item> {
        self.collect()
    }
}
impl<T: Iterator> IteratorExt for T {}

fn main() {
    let n = read!(String);
    let mut v = {
        let mut tmp = vec![];
        for d in n.chars() {
            let d = match d {
                '1' => 1,
                '2' => 2,
                '3' => 3,
                '4' => 4,
                '5' => 5,
                '6' => 6,
                '7' => 7,
                '8' => 8,
                '9' => 9,
                _ => 0,
            };
            tmp.push(d);
        }
        tmp
    };

    let sorted = {
        let mut tmp = v.clone();
        tmp.sort_by(|a, b| b.cmp(a));
        tmp
    };

    let i = {
        let mut tmp = 0;
        while v[tmp] == sorted[tmp] {
            tmp += 1;
            if tmp == v.len() { break; }
        }
        tmp
    };

    if i < v.len() {
        let j = {
            let mut tmp = v.len() - 1;
            loop {
                if v[tmp] == sorted[i] { break; }
                tmp -= 1;
            }
            tmp
        };
    
        // swap
        v[i] ^= v[j];
        v[j] ^= v[i];
        v[i] ^= v[j];    
    }

    let ans = v.iter().fold(0, |acc, e| acc * 10 + e);

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