source_code: import java.util.*;
  import java.io.*;
  
  public class A6 
  {
  	public static void main(String[] args)
  	{
  		Scanner in = new Scanner(System.in);
  		
  		int n = in.nextInt();
  		int d = in.nextInt();
  		int ans=2;
  		
  		int[] a = new int[n];
  		
  		for(int i=0;i<n;i++)
  			a[i] = in.nextInt();
  		
  		for(int i=1;i<n;i++)
  		{
  			if(a[i]-a[i-1]>2*d)
  			{
  				ans += 2;
  			}
  			else if(a[i]-a[i-1]==2*d)
  				ans += 1;
  		}
  		
  		System.out.println(ans);
  	}
  
  }
  