Хотя вывод верный..
package com.javarush.task.task04.task0420;
/*
Сортировка трех чисел
*/
import java.util.Scanner;
public class Solution {
public static void main(String[] args) throws Exception {
Scanner scanner = new Scanner(System.in);
int a = scanner.nextInt();
int b = scanner.nextInt();
int c = scanner.nextInt();
int m = Math.max(a,c);
int n = Math.max(a,b);
int p = Math.min(a,b);
System.out.println (m+" "+n+" "+p);
}
}