var v:array [1..1000000] of longint;
    n, m, d, k, i, j, t, a, b:longint;
    f, g:text;

begin
assign (f, 'zombie.in'); reset (f);
assign (g, 'zombie.out'); rewrite (g);

read (f, d, n, k);

a:=1;
for i := 1 to n do
  begin
  read (f, v[i]);

  while (v[a]+d <= v[i]) and (a<i) do
    begin
    if i-a+1 > k then begin t:=t+k; a:=i; end
                 else begin t:=t+1; a:=a+1; end;
    end;
  end;

if n-a+1 > k then t:=t+k else t:=t+n-a+1;

writeln (g, t);

close (f); close (g);
end.