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