#include <bits/stdc++.h>
using namespace std;
int main() {
  int count = 2;
  int n;
  int d;
  int a[101];
  cin >> n >> d;
  for (int i = 0; i < n; i++) cin >> a[i];
  for (int i = 0; i < n - 1; i++) {
    if (a[i + 1] - a[i] > 2 * d)
      count += 2;
    else if (a[i + 1] - a[i] == 2 * d)
      count += 1;
  }
  cout << count << endl;
  return 0;
}
