source_code: import java.io.*;
  import java.util.*;
  
  public class A {
  	public static void main(String[] args) {
  		InputStream inputStream = System.in;
  		OutputStream outputStream = System.out;
  		InputReader in = new InputReader(inputStream);
  		PrintWriter out = new PrintWriter(outputStream);
  		Task solver = new Task();
  		solver.solve(1, in, out);
  		out.close();
  	}
  
  	static class Task {
  		public void solve(int testNumber, InputReader in, PrintWriter out) {
  			int n = in.nextInt();
  			int d = in.nextInt();
  			int a[] = new int[n];
  			int c[] = new int[2 * n];
  			for (int i = 0; i < n; i++) {
  				a[i] = in.nextInt();
  				c[2 * i] = a[i] - d;
  				c[2 * i + 1] = a[i] + d;
  			}
  			Arrays.sort(c);
  			int ans = 0;
  			for (int i = 0; i < 2 * n; i++) {
  				if (i != 0 && c[i] == c[i - 1]) continue;
  				int mind = d + 1;
  				for (int j = 0; j < n; j++)
  					mind = Math.min(mind, Math.abs(a[j] - c[i]));
  				if (mind == d) {
  					ans += 1;
  				}
  			}
  			out.println(ans);
  		}
  	}
  
  	static class InputReader {
  		public BufferedReader reader;
  		public StringTokenizer tokenizer;
  
  		public InputReader(InputStream stream) {
  			reader = new BufferedReader(new InputStreamReader(stream), 32768);
  			tokenizer = null;
  		}
  
  		public String next() {
  			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
  				try {
  					tokenizer = new StringTokenizer(reader.readLine());
  				} catch (IOException e) {
  					throw new RuntimeException(e);
  				}
  			}
  			return tokenizer.nextToken();
  		}
  
  		public int nextInt() {
  			return Integer.parseInt(next());
  		}
  
  		public long nextLong() {
  			return Long.parseLong(next());
  		}
  
  	}
  }