This is the easy version of the problem. The difference between the versions is that in the easy version all prices a_i are different. You can make hacks if and only if you solved both versions of the problem.

Today is Sage's birthday, and she will go shopping to buy ice spheres. All n ice spheres are placed in a row and they are numbered from 1 to n from left to right. Each ice sphere has a positive integer price. In this version all prices are different.

An ice sphere is cheap if it costs strictly less than two neighboring ice spheres: the nearest to the left and the nearest to the right. The leftmost and the rightmost ice spheres are not cheap. Sage will choose all cheap ice spheres and then buy only them.

You can visit the shop before Sage and reorder the ice spheres as you wish. Find out the maximum number of ice spheres that Sage can buy, and show how the ice spheres should be reordered.

Input

The first line contains a single integer n (1 ≤ n ≤ 10^5) — the number of ice spheres in the shop.

The second line contains n different integers a_1, a_2, ..., a_n (1 ≤ a_i ≤ 10^9) — the prices of ice spheres.

Output

In the first line print the maximum number of ice spheres that Sage can buy.

In the second line print the prices of ice spheres in the optimal order. If there are several correct answers, you can print any of them.

Example

Input


5
1 2 3 4 5


Output


2
3 1 4 2 5 

Note

In the example it's not possible to place ice spheres in any order so that Sage would buy 3 of them. If the ice spheres are placed like this (3, 1, 4, 2, 5), then Sage will buy two spheres: one for 1 and one for 2, because they are cheap.

import java.util.*;
import java.lang.*;
import java.io.*;
 
 
public class Main
{
     
	public static void main (String[] args) throws java.lang.Exception
	{
		FastReader sc =new FastReader();
		
	   // int t=sc.nextInt();
	    
	    int t=1;
	    while(t-->0)
	    {
	        int n=sc.nextInt();
	        long arr[] = sc.readArrayLong(n);
	        Arrays.sort(arr);
	        long brr[] = new long[n];
	        
	        int k=0;
	        for(int i=0;i<n;i++)
	        {
	            if(k<n)
	            {
	                brr[k] = arr[n-i-1];
	                k+=2;
	            }
	            else
	            {
	                break;
	            }
	            
	        }
	        
	        int j=1;
	        for(int i=0;i<n;i++)
	        {
	            if(j<n)
	            {
	                brr[j] = arr[i];
	                j+=2;
	            }
	            else
	            {
	                break;
	            }
	        }
	        if(n%2==0)
	        {
	            System.out.println(n/2 - 1);
	            for(long e:brr)
    	        {
    	            System.out.print(e+" ");
    	        }
    	        System.out.println();
	        }
	        else
	        {
	            System.out.println(n/2);
	            for(long e:brr)
    	        {
    	            System.out.print(e+" ");
    	        }
    	        System.out.println();
	        }
	    }
	   
	    
	}
	
	
	
	
	static class FastReader {
        BufferedReader br;
        StringTokenizer st;
 
        public FastReader()
        {
            br = new BufferedReader(
                new InputStreamReader(System.in));
        }
 
        String next()
        {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        int nextInt() { return Integer.parseInt(next()); }
 
        long nextLong() { return Long.parseLong(next()); }
 
        double nextDouble()
        {
            return Double.parseDouble(next());
        }
        
        float nextFloat()
        {
            return Float.parseFloat(next());
        }
 
        String nextLine()
        {
            String str = "";
            try {
                str = br.readLine();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
        
        int[] readArray(int n) {
			int[] a=new int[n];
			for (int i=0; i<n; i++) a[i]=nextInt();
			return a;
		}
		
		long[] readArrayLong(int n) {
			long[] a=new long[n];
			for (int i=0; i<n; i++) a[i]=nextLong();
			return a;
		}
		
    }
    
    static boolean isPalindrome(String str)
    {
 
        // Pointers pointing to the beginning
        // and the end of the string
        int i = 0, j = str.length() - 1;
 
        // While there are characters to compare
        while (i < j) {
 
            // If there is a mismatch
            if (str.charAt(i) != str.charAt(j))
                return false;
 
            // Increment first pointer and
            // decrement the other
            i++;
            j--;
        }
 
        // Given string is a palindrome
        return true;
    }
    
    static boolean palindrome_array(int arr[], int n)
    {
        // Initialise flag to zero.
        int flag = 0;
 
        // Loop till array size n/2.
        for (int i = 0; i <= n / 2 && n != 0; i++) {
 
            // Check if first and last element are different
            // Then set flag to 1.
            if (arr[i] != arr[n - i - 1]) {
                flag = 1;
                break;
            }
        }
 
        // If flag is set then print Not Palindrome
        // else print Palindrome.
        if (flag == 1)
            return false;
        else
            return true;
    }
    
	static boolean allElementsEqual(int[] arr,int n)
	{
	    int z=0;
	        for(int i=0;i<n-1;i++)
		    {
		        if(arr[i]==arr[i+1])
		        {
		            z++;
		        }
		    }
		    if(z==n-1)
		    {
		        return true;
		    }
		    else
		    {
		        return false;
		    }
		    
	}
	
	static boolean allElementsDistinct(int[] arr,int n)
	{
	    int z=0;
	        for(int i=0;i<n-1;i++)
		    {
		        if(arr[i]!=arr[i+1])
		        {
		            z++;
		        }
		    }
		    if(z==n-1)
		    {
		        return true;
		    }
		    else
		    {
		        return false;
		    }
		    
		    
	}
	
	public static void reverse(int[] array)
    {
  
        // Length of the array
        int n = array.length;
  
        // Swaping the first half elements with last half
        // elements
        for (int i = 0; i < n / 2; i++) {
  
            // Storing the first half elements temporarily
            int temp = array[i];
  
            // Assigning the first half to the last half
            array[i] = array[n - i - 1];
  
            // Assigning the last half to the first half
            array[n - i - 1] = temp;
        }
    }
    
    public static void reverse_Long(long[] array)
    {
  
        // Length of the array
        int n = array.length;
  
        // Swaping the first half elements with last half
        // elements
        for (int i = 0; i < n / 2; i++) {
  
            // Storing the first half elements temporarily
            long temp = array[i];
  
            // Assigning the first half to the last half
            array[i] = array[n - i - 1];
  
            // Assigning the last half to the first half
            array[n - i - 1] = temp;
        }
    }
	
	static boolean isSorted(int[] a)
    {
        for (int i = 0; i < a.length - 1; i++)
        {
            if (a[i] > a[i + 1]) {
                return false;
            }
        }
 
        return true;
    }
    
    static boolean isReverseSorted(int[] a)
    {
        for (int i = 0; i < a.length - 1; i++)
        {
            if (a[i] < a[i + 1]) {
                return false;
            }
        }
 
        return true;
    }
    
    static int[] rearrangeEvenAndOdd(int arr[], int n)
    {
        ArrayList<Integer> list = new ArrayList<>();
		    
		    for(int i=0;i<n;i++)
		    {
		        if(arr[i]%2==0)
		        {
		            list.add(arr[i]);
		        }
		    }
		    
		    for(int i=0;i<n;i++)
		    {
		        if(arr[i]%2!=0)
		        {
		            list.add(arr[i]);
		        }
		    }
		    int len = list.size();
		    int[] array = list.stream().mapToInt(i->i).toArray();
		    return array;
    }
    
    static long[] rearrangeEvenAndOddLong(long arr[], int n)
    {
        ArrayList<Long> list = new ArrayList<>();
		    
		    for(int i=0;i<n;i++)
		    {
		        if(arr[i]%2==0)
		        {
		            list.add(arr[i]);
		        }
		    }
		    
		    for(int i=0;i<n;i++)
		    {
		        if(arr[i]%2!=0)
		        {
		            list.add(arr[i]);
		        }
		    }
		    int len = list.size();
		    long[] array = list.stream().mapToLong(i->i).toArray();
		    return array;
    }
	
	
    
    static boolean isPrime(long n)
    {
 
        // Check if number is less than
        // equal to 1
        if (n <= 1)
            return false;
 
        // Check if number is 2
        else if (n == 2)
            return true;
 
        // Check if n is a multiple of 2
        else if (n % 2 == 0)
            return false;
 
        // If not, then just check the odds
        for (long i = 3; i <= Math.sqrt(n); i += 2)
        {
            if (n % i == 0)
                return false;
        }
        return true;
    }
    
    static int getSum(int n)
    {    
        int sum = 0;
          
        while (n != 0)
        {
            sum = sum + n % 10;
            n = n/10;
        }
      
    return sum;
    }
    
    static int gcd(int a, int b)
    {
      if (b == 0)
        return a;
      return gcd(b, a % b);
    }
     
    static long gcdLong(long a, long b)
    {
        if(b==0)
        {
            return a;
        }
        else 
        
        {
            return gcdLong(b,a%b);
        }
    }
    
    static void swap(int[] arr, int i, int j)
    {
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }
	
	static int countDigit(long n)
    {
        return (int)Math.floor(Math.log10(n) + 1);
    }
	
}