import java.io.*;
import java.util.*;

class Main {
	
	public static void out (Object o) {
		System.out.println(o);
	}
	
	public static void solve (int n) {
		char[] c = (n + "").toCharArray();
		for (int i = 0; i < c.length - 1; i++) {
			int d = c[i] - '0';
			int max = d , maxI = -1;
			for (int j = c.length - 1; j > i; j--) {
				int e = c[j] - '0';
				if (max < e) {
					max = e;
					maxI = j;
				}
			}
			if (maxI != -1) {
				char tmp = c[i];
				c[i] = c[maxI];
				c[maxI] = tmp;
				break;
			}
		}
		
		for (char d : c)
			System.out.print(d);
		out("");
	}
	
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		int n = Integer.parseInt(br.readLine());
		
		solve(n);
	}
}