source_code: //package CodeforcesJava;
  
  import java.io.*;
  import java.util.*;
  
  public class Main {
  
      public void solve(InputProvider input, PrintWriter output) throws IOException {
          int n = input.nextInt();
          int d = input.nextInt();
          int count = 1;
          int current = input.nextInt();
          for (int i = 1; i < n; i++) {
              int x = input.nextInt();
              if (x - current == d * 2) {
                  count++;
              } else if (x - current > d * 2) {
                  count += 2;
              }
              current = x;
          }
          count++;
          output.print(count);
      }
  
      public static void main(String[] args) throws Exception {
          try (InputProvider input = new InputProvider(System.in);
               PrintWriter output = new PrintWriter(System.out)) {
              new Main().solve(input, output);
          }
      }
  
      public static class InputProvider implements AutoCloseable {
  
          private final BufferedReader reader;
          private StringTokenizer tokenizer;
  
          public InputProvider(Reader reader) {
              this.reader = new BufferedReader(reader);
          }
  
          public InputProvider(InputStream input) {
              reader = new BufferedReader(new InputStreamReader(input));
          }
  
          public String next() throws IOException {
              if (Objects.isNull(tokenizer) || !tokenizer.hasMoreTokens())
                  tokenizer = new StringTokenizer(reader.readLine());
              return tokenizer.nextToken();
          }
  
          public int nextInt() throws IOException {
              return Integer.parseInt(next());
          }
  
          public long nextLong() throws IOException {
              return Long.parseLong(next());
          }
  
          public double nextDouble() throws IOException {
              return Double.parseDouble(next());
          }
  
          public String nextLine() throws IOException {
              return reader.readLine();
          }
  
          @Override
          public void close() throws Exception {
              reader.close();
          }
  
      }
  
  }
  