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.
// Don't place your source in a package
import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*; 
 
// Please name your class Main
public class Main {
	
	static StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
    
 
    static int read() throws IOException {
        in.nextToken();
        return (int) in.nval;
    }
    static String readString() throws IOException {
        in.nextToken();
        return in.sval;
	}
	
	
	public static void main (String[] args) throws java.lang.Exception {
	    Scanner in = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		//InputReader in = new InputReader(System.in);
 
		
		int T=1;
		for(int t=0;t<T;t++){
			int n=in.nextInt();
			int A[]=new int[n];
			for(int i=0;i<n;i++){
				A[i]=in.nextInt();
			}
			
			Solution sol=new Solution();
			sol.solution(A);
	
		}
		
 
	
 
		out.flush();
	}
 
}
 
class Solution{
	//constant variable
	final int MAX=Integer.MAX_VALUE;
	final int MIN=Integer.MIN_VALUE;
	//Set<Integer>adjecent[];
	//////////////////////////////
	
	

	public void solution(int A[]){
		
		Arrays.sort(A);
		int res[]=new int[A.length];
		int index=0;
		int cnt=0;
		for(int i=1;i<res.length;i+=2){
			res[i]=A[index++];
			if(i!=res.length-1)cnt++;
		}
		for(int i=0;i<res.length;i+=2){
			res[i]=A[index++];
		}
		msg(cnt+"");
		for(int i:res){
			System.out.print(i+" ");
		}
		msg("");
	}
	
	
	
 
 
 
	
	
	
	
	
	
	
	
	
	
	public void swap(int A[],int l,int r){
		int t=A[l];
		A[l]=A[r];
		A[r]=t;
	}
	
	
	public long C(long fact[],int i,int j){ // C(20,3)=20!/(17!*3!)
		// take   a/b     where a=20!  b=17!*3!
		if(j>i)return 0;
		if(j==0)return 1;
		long mod=998244353;
		long a=fact[i];
		long b=((fact[i-j]%mod)*(fact[j]%mod))%mod;
		BigInteger B= BigInteger.valueOf(b);
		long binverse=B.modInverse(BigInteger.valueOf(mod)).longValue();
		return ((a)*(binverse%mod))%mod;
	}
	
	 
	
	//map operation
	public void put(Map<Integer,Integer>map,int i){
		if(!map.containsKey(i))map.put(i,0);
		map.put(i,map.get(i)+1);
	}
	
	public void delete(Map<Integer,Integer>map,int i){
		map.put(i,map.get(i)-1);
		if(map.get(i)==0)map.remove(i);
	}
 
 

	
 
	
 
 
	/*public void tarjan(int p,int r){
		if(cut)return;
		List<Integer>childs=adjecent[r];
		dis[r]=low[r]=time;
		time++;
		
		//core for tarjan
		int son=0;
		for(int c:childs){
			if(ban==c||c==p)continue;
			if(dis[c]==-1){
				son++;
				tarjan(r,c);
				low[r]=Math.min(low[r],low[c]);
				if((r==root&&son>1)||(low[c]>=dis[r]&&r!=root)){
					cut=true;
					return;
				}
			}else{
				if(c!=p){
					low[r]=Math.min(low[r],dis[c]);
				}
			}
		}
		
	}*/
	
	
 
	
	
		
	
	//helper function I would use
	public void remove(Map<Integer,Integer>map,int i){
		map.put(i,map.get(i)-1);
		if(map.get(i)==0)map.remove(i);
	}
	
	
	
	public void ascii(String s){
		for(char c:s.toCharArray()){
			System.out.print((c-'a')+" ");
		}
		msg("");
	}
	
	public int flip(int i){
		if(i==0)return 1;
		else return 0;
	}
	
	public boolean[] primes(int n){
		boolean A[]=new boolean[n+1];
		for(int i=2;i<=n;i++){
			if(A[i]==false){
				for(int j=i+i;j<=n;j+=i){
					A[j]=true;
				}
			}
		}
		return A;
	}
	
	public void msg(String s){
		System.out.println(s);
	}
	
	public void msg1(String s){
		System.out.print(s);
	}
	
	public int[] kmpPre(String p){
		int pre[]=new int[p.length()];
		int l=0,r=1;
		while(r<p.length()){
			if(p.charAt(l)==p.charAt(r)){
				pre[r]=l+1;
				l++;r++;
			}else{
				if(l==0)r++;
				else l=pre[l-1];
			}
		}
		return pre;
	}
	
	public boolean isP(String s){
		int l=0,r=s.length()-1;
		while(l<r){
			if(s.charAt(l)!=s.charAt(r))return false;
			l++;r--;
		}
		return true;
	}
	
	public int find(int nums[],int x){//union find => find method
		if(nums[x]==x)return x;
		int root=find(nums,nums[x]);
		nums[x]=root;
		return root;
	}
	
	public boolean check(int grid[][],int r,int c){
		if(r<0||c<0||r>=grid.length||c>=grid[0].length)return false;
		return true;
	}
	
	public int get(int A[],int i){
		if(i<0||i>=A.length)return 0;
		return A[i];
	}
	public int[] copy1(int A[]){
		int a[]=new int[A.length];
		for(int i=0;i<a.length;i++)a[i]=A[i];
		return a;
	}
	
	public int[] copy2(int A[]){
		int a[]=new int[A.length];
		for(int i=0;i<a.length;i++)a[i]=A[i];
		return a;
	}
	
	
	public void print1(int A[]){
		for(long i:A)System.out.print(i+" ");
		System.out.println();
	}
	public void print2(long A[][]){
		for(int i=0;i<A.length;i++){
			for(int j=0;j<A[0].length;j++){
				System.out.print(A[i][j]+" ");
			}System.out.println();
		}
	}
	
	public int min(int a,int b){
		return Math.min(a,b);
	}
	
	
	public int[][] matrixdp(int[][] grid) {
        if(grid.length==0)return new int[][]{};
        int res[][]=new int[grid.length][grid[0].length];
        for(int i=0;i<grid.length;i++){
            for(int j=0;j<grid[0].length;j++){
                res[i][j]=grid[i][j]+get(res,i-1,j)+get(res,i,j-1)-get(res,i-1,j-1);
            }
        }
        return res;
    }
    
    public int get(int grid[][],int i,int j){
        if(i<0||j<0||i>=grid.length||j>=grid[0].length)return 0;
        return grid[i][j];
    }
	
	public int[] suffixArray(String s){
		int n=s.length();
		Suffix A[]=new Suffix[n];
		
		for(int i=0;i<n;i++){
			A[i]=new Suffix(i,s.charAt(i)-'a',0);
		}
		
		for(int i=0;i<n;i++){
			if(i==n-1){
				A[i].next=-1;
			}else{
				A[i].next=A[i+1].rank;
			}
		}
		Arrays.sort(A);
		
		for(int len=4;len<A.length*2;len<<=1){
			int in[]=new int[A.length];
			int rank=0;
			int pre=A[0].rank;
			A[0].rank=rank;
			in[A[0].index]=0;
			for(int i=1;i<A.length;i++){//rank for the first two letter
				if(A[i].rank==pre&&A[i].next==A[i-1].next){
					pre=A[i].rank;
					A[i].rank=rank;
				}else{
					pre=A[i].rank;
					A[i].rank=++rank;
				}
				in[A[i].index]=i;
			}
			
			for(int i=0;i<A.length;i++){
				int next=A[i].index+len/2;
				if(next>=A.length){
					A[i].next=-1;
				}else{
					A[i].next=A[in[next]].rank;
				}
			}
			
			
			Arrays.sort(A);
		}
		
		
		int su[]=new int[A.length];
		for(int i=0;i<su.length;i++){
			su[i]=A[i].index;
		}
		return su;
	}
	
}
 
//suffix array Struct
class Suffix implements Comparable<Suffix>{
	int index;
	int rank;
	int next;
	public Suffix(int i,int rank,int next){
		this.index=i;
		this.rank=rank;
		this.next=next;
	}
	
	@Override
	public int compareTo(Suffix other) {
		if(this.rank==other.rank){
			return this.next-other.next;
		}
		return this.rank-other.rank;
	}
	
	public String toString(){
		return this.index+"   "+this.rank+"   "+this.next+"  ";
	}
}
 
 
 
class Wrapper implements Comparable<Wrapper>{
	int spf;int cnt;
	public Wrapper(int spf,int cnt){
		this.spf=spf;
		this.cnt=cnt;
	}
		
	@Override
	public int compareTo(Wrapper other) {
		return this.spf-other.spf;
	}
}
 
 
 
    class Node{//what the range would be for that particular node
		boolean state=false;
        int l=0,r=0;
		int ll=0,rr=0;
        public Node(boolean state){
            this.state=state;
        }
    }
	
	
	
	
	class Seg1{
			int A[];
			public Seg1(int A[]){
				this.A=A;
			}
			
			public void update(int left,int right,int val,int s,int e,int id){
				if(left<0||right<0||left>right)return;
				if(left==s&&right==e){
					
					A[id]+=val;
					return;
				}
				int mid=s+(e-s)/2; //[s,mid] [mid+1,e]
				
				if(left>=mid+1){
					update(left,right,val,mid+1,e,id*2+2);
				}else if(right<=mid){
					update(left,right,val,s,mid,id*2+1);
				}else{
					update(left,mid,val,s,mid,id*2+1);
					update(mid+1,right,val,mid+1,e,id*2+2);
				}
			}
			
			public int query(int i,int add,int s,int e,int id){
				
				if(s==e&&i==s){
					return A[id]+add;
				}
				
				int mid=s+(e-s)/2; //[s,mid] [mid+1,e]
				
				if(i>=mid+1){
					return query(i,A[id]+add,mid+1,e,id*2+2);
				}else{
					return query(i,A[id]+add,s,mid,id*2+1);
				}
			}
	}
 
 