Program zombie;
 var n,k,i,j,cap,l,p,aux:longint;
     sum,d:int64;
     a:array [1..1000000] of longint;
     b1:array [1..1 shl 17] of char;
     s:string;
     fi,fo:text;
function citire:longint;
 var aux:longint;
begin
 aux:=0;
 while (s[p]>='0') and (s[p]<='9') and (p<=l) do begin
                                            aux:=aux*10+ord(s[p])-48;
                                             if p=l then begin
                                             read(fi, s);
                                                 p:=0;
                                               l:=length(s);
                                                  end;
                                                 inc(p);
                                                  end;
while ((s[p]<'0') or (s[p]>'9'))and(s<>'') do begin
                                                inc(p);
                                                if p>l then begin
                                                   read(fi, s);
                                                      p:=1;
                                                      l:=length(s);
                                                            end;
                                                  end;
citire:=aux;
end;
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);   }
 read(fi,s); l:=length(s); p:=1;
  for i:=1 to n do a[i]:=citire;
close(fo);
end.