source_code: import java.io.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.io.OutputStream;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.FileNotFoundException;
  import java.util.StringTokenizer;
  import java.io.Writer;
  import java.io.BufferedReader;
  import java.io.InputStream;
  
  /**
   * Built using CHelper plug-in
   * Actual solution is at the top
   *
   * @author Asgar Javadov
   */
  public class Main {
      public static void main(String[] args) {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          InputReader in = new InputReader(inputStream);
          OutputWriter out = new OutputWriter(outputStream);
          TaskA solver = new TaskA();
          solver.solve(1, in, out);
          out.close();
      }
  
      static class TaskA {
          public void solve(int testNumber, InputReader in, OutputWriter out) {
              int n = in.nextInt();
              int d = in.nextInt();
              int[] a = in.readIntArray(n);
  
              int ans = 1;
              for (int i = 0; i < a.length - 1; ++i) {
                  int left = a[i] + d;
                  int right = a[i + 1] - d;
                  if (left < right) {
                      ans += 2;
                  } else if (left == right)
                      ans++;
              }
  
              out.println(ans + 1);
          }
  
      }
  
      static class OutputWriter extends PrintWriter {
          public OutputWriter(OutputStream outputStream) {
              super(outputStream);
          }
  
          public OutputWriter(Writer writer) {
              super(writer);
          }
  
          public OutputWriter(String filename) throws FileNotFoundException {
              super(filename);
          }
  
          public void close() {
              super.close();
          }
  
      }
  
      static class InputReader extends BufferedReader {
          StringTokenizer tokenizer;
  
          public InputReader(InputStream inputStream) {
              super(new InputStreamReader(inputStream), 32768);
          }
  
          public InputReader(String filename) {
              super(new InputStreamReader(Thread.currentThread().getContextClassLoader().getResourceAsStream(filename)));
          }
  
          public String next() {
              while (tokenizer == null || !tokenizer.hasMoreTokens()) {
                  try {
                      tokenizer = new StringTokenizer(readLine());
                  } catch (IOException e) {
                      throw new RuntimeException();
                  }
              }
              return tokenizer.nextToken();
          }
  
          public Integer nextInt() {
              return Integer.valueOf(next());
          }
  
          public int[] readIntArray(int size) {
              int[] array = new int[size];
              for (int i = 0; i < size; i++)
                  array[i] = nextInt();
              return array;
          }
  
      }
  }
  
  