C++ :

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>

using namespace std;
int n,r;
int a[1010];
int main(){
	cin>>n>>r;
	for(int i=1;i<=n;i++)cin>>a[i];
	sort(a+1,a+1+n);
	//for(int i=1;i<=n;i++)cout<<a[i]<<' ';
	int x=0,num=0;
	for(int i=1;i<=n&&x<10000;){
		//cout<<i<<' ';
		while(a[i]-r<=x){
			i++;
		}
		num++;
		x=a[i-1]+r;
	}
	cout<<num;
	return 0;
}

Pascal :

var
  i,j,n,r,ans,t:longint;
	x,y:array[0..1001]of longint;
procedure qsort(l,r:longint);
var
  i,j,mid,tmp:longint;
begin
  i:=l;j:=r;
  mid:=x[(l+r) div 2];
  repeat
    while x[i]<mid do inc(i);
    while x[j]>mid do dec(j);
    if i<=j then
    begin
      tmp:=x[i];x[i]:=x[j];x[j]:=tmp;
      tmp:=y[i];y[i]:=y[j];y[j]:=tmp;
      inc(i);dec(j);
    end;
  until i>j;
  if l<j then qsort(l,j);
  if i<r then qsort(i,r);
end;
begin
  readln(n,r);
	for i:=1 to n do
	begin
	  read(t);
		x[i]:=t-r; y[i]:=t+r;
	end;
	qsort(1,n);
	if n=1 then begin write(1);halt; end;
	ans:=0;
	t:=0;
	for i:=2 to n do
	  if (x[i-1]<=t)and(x[i]>t) then
		begin
		  inc(ans);
			t:=y[i-1];
		end;
	if t<10000 then inc(ans);
	write(ans);
end.