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