source_code: import java.io.OutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.PrintWriter;
  import java.io.FilterInputStream;
  import java.io.BufferedInputStream;
  import java.io.InputStream;
  
  /**
   * @author khokharnikunj8
   */
  public class Main {
      public static void main(String[] args) {
          new Thread(null, new Runnable() {
              public void run() {
                  new Main().solve();
              }
          }, "1", 1 << 26).start();
      }
  
      void solve() {
          InputStream inputStream = System.in;
          OutputStream outputStream = System.out;
          ScanReader in = new ScanReader(inputStream);
          PrintWriter out = new PrintWriter(outputStream);
          ASonyaAndHotels solver = new ASonyaAndHotels();
          solver.solve(1, in, out);
          out.close();
      }
  
      static class ASonyaAndHotels {
          public void solve(int testNumber, ScanReader in, PrintWriter out) {
              int n = in.scanInt();
              int d = in.scanInt();
              int[] ar = new int[n];
              int ans = 2;
              for (int i = 0; i < n; i++) ar[i] = in.scanInt();
              for (int i = 0; i < n - 1; i++) {
                  if (ar[i + 1] - ar[i] == 2 * d) ans++;
                  else if (ar[i + 1] - ar[i] > 2 * d) ans += 2;
              }
              out.println(ans);
          }
  
      }
  
      static class ScanReader {
          private byte[] buf = new byte[4 * 1024];
          private int index;
          private BufferedInputStream in;
          private int total;
  
          public ScanReader(InputStream inputStream) {
              in = new BufferedInputStream(inputStream);
          }
  
          private int scan() {
              if (index >= total) {
                  index = 0;
                  try {
                      total = in.read(buf);
                  } catch (Exception e) {
                      e.printStackTrace();
                  }
                  if (total <= 0) return -1;
              }
              return buf[index++];
          }
  
          public int scanInt() {
              int integer = 0;
              int n = scan();
              while (isWhiteSpace(n)) n = scan();
              int neg = 1;
              if (n == '-') {
                  neg = -1;
                  n = scan();
              }
              while (!isWhiteSpace(n)) {
                  if (n >= '0' && n <= '9') {
                      integer *= 10;
                      integer += n - '0';
                      n = scan();
                  }
              }
              return neg * integer;
          }
  
          private boolean isWhiteSpace(int n) {
              if (n == ' ' || n == '\n' || n == '\r' || n == '\t' || n == -1) return true;
              else return false;
          }
  
      }
  }
  
  