source_code: import java.util.*;
  import java.io.*;
  
  public class Main {
  
      public static void main(String[] args)
      {
          InputReader in = new InputReader(System.in);
          OutputWriter out = new OutputWriter(System.out);
           int n = in.nextInt();
           int d = in.nextInt();
           int[]a = new int[n];
           int ans=2;
  
           for (int i =0;i<n;i++)
           {
               a[i] = in.nextInt();
  
           }
           for (int i =0;i<n-1;i++)
           {
  
               if (a[i+1]-a[i]==2*d)
                   ans++;
               if (a[i+1]-a[i]>2*d)
                   ans+=2;
           }
           out.printLine(ans);
          out.flush();
      }
  
  }
  
  class pair  implements Comparable
  {
  
      int key;
      int value;
      public pair(Object key, Object value) {
  
          this.key = (int)key;
          this.value=(int)value;
      }
  
      @Override
      public int compareTo(Object o) {
          pair temp =(pair)o;
          return  key-temp.key;
      }
  }
  class Graph {
  
  
      int n;
      ArrayList<Integer>[] adjList;
  
      public Graph(int n) {
          this.n = n;
          adjList = new ArrayList[n];
          for (int i = 0; i < n; i++)
              adjList[i] = new ArrayList<>();
      }
  
  }
  
  
  class InputReader {
  
      private final InputStream stream;
      private final byte[] buf = new byte[8192];
      private int curChar, snumChars;
  
      public InputReader(InputStream stream) {
          this.stream = stream;
      }
  
      public int read() {
          if (snumChars == -1)
              throw new InputMismatchException();
          if (curChar >= snumChars) {
              curChar = 0;
              try {
                  snumChars = stream.read(buf);
              } catch (IOException e) {
                  throw new InputMismatchException();
              }
              if (snumChars <= 0)
                  return -1;
          }
          return buf[curChar++];
      }
  
      public int nextInt() {
          int c = read();
          while (isSpaceChar(c)) {
              c = read();
          }
          int sgn = 1;
          if (c == '-') {
              sgn = -1;
              c = read();
          }
          int res = 0;
          do {
              res *= 10;
              res += c - '0';
              c = read();
          } while (!isSpaceChar(c));
          return res * sgn;
      }
  
      public long nextLong() {
          int c = read();
          while (isSpaceChar(c)) {
              c = read();
          }
          int sgn = 1;
          if (c == '-') {
              sgn = -1;
              c = read();
          }
          long res = 0;
          do {
              res *= 10;
              res += c - '0';
              c = read();
          } while (!isSpaceChar(c));
          return res * sgn;
      }
  
      public int[] nextIntArray(int n) {
          int a[] = new int[n];
          for (int i = 0; i < n; i++) {
              a[i] = nextInt();
          }
          return a;
      }
  
      public String readString() {
          int c = read();
          while (isSpaceChar(c)) {
              c = read();
          }
          StringBuilder res = new StringBuilder();
          do {
              res.appendCodePoint(c);
              c = read();
          } while (!isSpaceChar(c));
          return res.toString();
      }
  
      public String nextLine() {
          int c = read();
          while (isSpaceChar(c))
              c = read();
          StringBuilder res = new StringBuilder();
          do {
              res.appendCodePoint(c);
              c = read();
          } while (!isEndOfLine(c));
          return res.toString();
      }
  
      public boolean isSpaceChar(int c) {
          return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
      }
  
      private boolean isEndOfLine(int c) {
          return c == '\n' || c == '\r' || c == -1;
      }
  
  }
  
  class OutputWriter {
      private final PrintWriter writer;
  
      public OutputWriter(OutputStream outputStream) {
          writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
      }
  
      public OutputWriter(Writer writer) {
          this.writer = new PrintWriter(writer);
      }
  
      public void print(Object... objects) {
          for (int i = 0; i < objects.length; i++) {
              if (i != 0)
                  writer.print(' ');
              writer.print(objects[i]);
          }
      }
  
      public void printLine(Object... objects) {
          print(objects);
          writer.println();
      }
  
      public void close() {
          writer.close();
      }
  
      public void flush() {
          writer.flush();
      }
  
  }