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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import static java.lang.Math.*;
import static java.lang.System.out;
import java.util.*;
import java.io.PrintStream;
import java.io.PrintWriter;
public class A {
 
	static final int mod = 1000000007;
	static final long temp = 998244353;
	static final long MOD = 1000000007;
	static final long M = (long)1e9+7;
 
	
	static class Pair implements Comparable<Pair>
	{
		int first, second;
		public Pair(int aa, int bb)
		{
			first = aa; second = bb;
		}
		public int compareTo(Pair p)
		{
			if(first == p.first) return (int)(second - p.second);
			return (int)(first - p.first);
		}
	}
	
	/*
	 * IO FOR 2D GRID IN JAVA
	 * 	char[][] grid = new char[n][m];
			for(int i = 0;i<n;i++)
			{
				char[] s = sc.next().toCharArray();
				for(int j = 0;j<m;j++)
				{
					grid[i][j] = s[j];
				}
			}
	 * */
	
	static class Reader {
		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st=new StringTokenizer("");
		String next() {
			while (!st.hasMoreTokens())
				try {
					st=new StringTokenizer(br.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			return st.nextToken();
		}
		
		int nextInt() {
			return Integer.parseInt(next());
		}
		
		int[] readArray(int n) throws IOException {
			int[] a=new int[n];
			for (int i=0; i<n; i++) a[i]=nextInt();
			return a;
		}
		
		long[] longReadArray(int n) throws IOException {
			long[] a=new long[n];
			for (int i=0; i<n; i++) a[i]=nextLong();
			return a;
		}
		
		
		long nextLong() {
			return Long.parseLong(next());
		}
		double nextDouble() {
			return Double.parseDouble(next());
		}
	}
	
 
		public static boolean isPrime(int n) 
		{
			if(n == 1)
			{
				return false;
			}
			for(int i = 2;i*i<=n;i++)
			{
				if(n%i == 0)
				{
					return false;
				}
			}
			return true;
	}
	
	public static List<Integer> SieveList(int n)
	{
		boolean prime[] = new boolean[n+1];
		Arrays.fill(prime, true);
		
		List<Integer> l = new ArrayList<>();
		for (int p=2; p*p<=n; p++) 
		{ 
			if (prime[p] == true) 
			{ 	
			    for(int i=p*p; i<=n; i += p) 
				{
				    prime[i] = false; 
				}	
			} 
		} 
 
		for (int p=2; p<=n; p++) 
		{
		    if (prime[p] == true)
		    {
		       l.add(p); 
		    }
		}
		
		return l;
	}
	
	
	public static int gcd(int a, int b)
	{
		if(b == 0)
		 return a;
		
		else
		return gcd(b,a%b);
	} 
 
		public static int lcm(int a, int b)
	    {
	        return (a / gcd(a, b)) * b;
	    }
	
	public static long LongGCD(long a, long b)
	{
		if(b == 0)
			 return a;
			
			else
			return LongGCD(b,a%b);
	}
	
		public static long LongLCM(long a, long b)
	    {
	        return (a / LongGCD(a, b)) * b;
	    }
	
		public static int phi(int n)  //euler totient function
	    { 
	        int result = 1; 
	        for (int i = 2; i < n; i++) 
	            if (gcd(i, n) == 1) 
	                result++; 
	        return result; 
	    }
	
	public static long fastPow(long x, long n) //include mod at each step if asked and in args of fn too
	{
		if(n == 0)
			return 1;
		else if(n%2 == 0)
			return fastPow(x*x,n/2);
		else
			return x*fastPow(x*x,(n-1)/2);
	}
	
	
	   public static long modPow(long x, long y, long p)
	    {
	        long res = 1;
	        x = x % p;
	 
	        while (y > 0) {
	            if (y % 2 == 1)
	                res = (res * x) % p;
	 
	            y = y >> 1; 
	            x = (x * x) % p;
	        }
	        return res;
	    }
	   
	   static long modInverse(long n, long p)
	    {
	        return modPow(n, p - 2, p);
	    }
	 
	    // Returns nCr % p using Fermat's little theorem.
	    
	    public static long nCrModP(long n, long r,long p)
	    {
	          if (n<r) 
	              return 0;
	          
	        if (r == 0)
	            return 1;
	 
	        long[] fac = new long[(int)(n) + 1];
	        fac[0] = 1;
	 
	        for (int i = 1; i <= n; i++)
	            fac[i] = fac[i - 1] * i % p;
	 
	        return (fac[(int)(n)] * modInverse(fac[(int)(r)], p)
	                % p * modInverse(fac[(int)(n - r)], p)
	                % p)
	            % p;
	    }
	    
	    public static long nCr(long n, long r)
	    {
	    	long ans = 1;
	    	for(long i = 1,j = n;i<=r;i++,j--)
	    	{
	    		ans = ans * j / i;
	    	}
	    	return ans;
	    }
 
		public static void Sort(int[] a) {
			List<Integer> l=new ArrayList<>();
			for (int i : a) l.add(i);
			Collections.sort(l);
//			Collections.reverse(l);  //Use to Sort decreasingly 
			for (int i=0; i<a.length; i++) a[i]=l.get(i);
		}
		
		public static void ssort(char[] a)
		{
			List<Character> l = new ArrayList<>();
			for (char i : a) l.add(i);
			Collections.sort(l);
			for (int i=0; i<a.length; i++) a[i]=l.get(i);
		}
		
		
		//Modular Operations for Addition and Multiplication. 
		
		   public static long perfomMod(long x)
		   {
		        return ((x%M + M)%M);
		    }
		   public static long addMod(long a, long  b)
		   {
		        return perfomMod(perfomMod(a)+perfomMod(b));
		    }
		   public static long mulMod(long  a, long b)
		   {
		        return perfomMod(perfomMod(a)*perfomMod(b));
		   }
		
		   public static int LowerBound(int a[], int x) 
		   {
				  int l=-1,r=a.length;
				  while(l+1<r) {
				    int m=(l+r)>>>1;
				    if(a[m]>=x) r=m;
				    else l=m;
				  }
				  return r;
			}
		
		   
			public static int UpperBound(int a[], int x) 
			{
			    int l=-1;
			    int r=a.length;
			    while(l+1<r) {
			       int m=(l+r)>>>1;
			       if(a[m]<=x) l=m;
			       else r=m;
			    }
			    return l+1;
		}
	
			public static class DSU
			{
				int[] parent;
				int[] rank; //Size of the trees is used as the rank
				public DSU(int n)
				{
					parent = new int[n];
					rank = new int[n];
					Arrays.fill(parent, -1);
					Arrays.fill(rank, 1);
				}
				
				public int find(int i) //finding through path compression
				{
					return parent[i] < 0 ? i : (parent[i] = find(parent[i]));
				}
				
				public boolean union(int a, int b)
				{
					a = find(a);
					b = find(b);
					
					if(a == b) return false; //if they are already connected we exit by returning false.
					
					if(parent[a] == parent[b]) parent[a]--;
					if(parent[a] <= parent[b]) 
					{
						// a would be parent
						rank[a] += rank[b];
						parent[b] = a;
					}
					else
					{
						//b would be parent
						rank[b] += rank[a];
						parent[a] = b;
					}
					return true;
				}	
			}
		
		
	
	public static void main(String[] args) throws IOException 
	{
		Reader sc = new Reader();
		PrintWriter fout = new PrintWriter(System.out);
		    
		int n = sc.nextInt();
		int[] a = sc.readArray(n);
		PriorityQueue<Integer> pq = new PriorityQueue<>();
		
		for(int xt : a)
		{
			pq.add(xt);
		}
		
		int[] ans = new int[n];
		
		for(int i = 1;i<n;i+=2)
		{
			ans[i] = pq.poll();
		}
		
		for(int i = 0;i<n;i+=2)
		{
			ans[i] = pq.poll();
		}
		
		fout.println((n - 1)/2);
		
		for(int x : ans)
		{
			fout.print(x + " ");
		}
		
		fout.println();
		fout.close();
	}
}