Program zombie;
 var n,k,i,j,cap:longint;
     sum,d:int64;
     a:array [1..1000000] of longint;
     b1:array [1..1 shl 18] of char;
     fi,fo:text;
begin
 assign(fi,'zombie.in');
  assign(fo,'zombie.out');
 settextbuf(fi,b1);
 reset(fi); rewrite(fo);
 readln(fi,d,n,k); read(fi,cap); j:=1;
 for i:=1 to n-1 do begin
                     read(fi,a[i]);
                     if (a[i]-cap>=d) or (i=n-1) then begin
                                if j>k then sum:=sum+k
                                         else sum:=sum+j;
                                            cap:=a[i];
                                             j:=1;
                                            end
                      else inc(j);
                      end;
 write(fo,sum);
close(fo);
end.