source_code: import java.io.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.util.HashMap;
  import java.util.InputMismatchException;
  import java.io.IOException;
  import java.io.InputStream;
  
  /**
   * Built using CHelper plug-in
   * Actual solution is at the top
   *
   * @author ankur
   */
  public class Main {
      public static void main(String[] args) {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          InputReader in = new InputReader(inputStream);
          PrintWriter out = new PrintWriter(outputStream);
          TaskA solver = new TaskA();
          solver.solve(1, in, out);
          out.close();
      }
  
      static class TaskA {
          public void solve(int testNumber, InputReader in, PrintWriter out) {
              int n = in.nextInt();
              long k = in.nextLong();
              HashMap<Long, Integer> hm = new HashMap<>();
              long ar[] = in.nextLongArray(n);
              for (int i = 0; i < n; i++) {
                  long dist = ar[i] + k;
                  long min = k;
                  for (int j = 0; j < n; j++) {
                      min = Math.min(min, Math.abs(ar[j] - dist));
                  }
                  if (min == k) {
                      hm.put(dist, 1);
                  }
                  dist = ar[i] - k;
                  min = k;
                  for (int j = 0; j < n; j++) {
                      min = Math.min(min, Math.abs(ar[j] - dist));
                  }
                  if (min == k) {
                      hm.put(dist, 1);
                  }
              }
              out.print(hm.size());
          }
  
      }
  
      static class InputReader {
          private final InputStream stream;
          private final byte[] buf = new byte[8192];
          private int curChar;
          private int snumChars;
  
          public InputReader(InputStream st) {
              this.stream = st;
          }
  
          public int read() {
              //*-*------clare------
  //remeber while comparing 2 non primitive data type not to use ==
  //remember Arrays.sort for primitive data has worst time case complexity of 0(n^2) bcoz it uses quick sort
  //again silly mistakes ,yr kb tk krta rhega ye mistakes
  //try to write simple codes ,break it into simple things
  //knowledge>rating
          /*
          public class Main
          implements Runnable{
      public static void main(String[] args) {
          new Thread(null,new Main(),"Main",1<<26).start();
  
      }
      public void run() {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          InputReader in = new InputReader(inputStream);
          PrintWriter out = new PrintWriter(outputStream);
          TaskC solver = new TaskC();//chenge the name of task
          solver.solve(1, in, out);
          out.close();
      }
           */
  
              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 long[] nextLongArray(int n) {
              long a[] = new long[n];
              for (int i = 0; i < n; i++) {
                  a[i] = nextLong();
              }
              return a;
          }
  
          public boolean isSpaceChar(int c) {
              return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
          }
  
      }
  }
  
  