var f,g:text;
    n,k,a,b,i,j,s,sc,nr:longint;
    v:array[1..500002] of longint;
begin
     assign(f,'divk.in'); reset(f);
     assign(g,'divk.out'); rewrite(g);
     readln(f,n,k,a,b);
     for i:=1 to n do readln(f,v[i]);
     nr:=0;   s:=0;
     for i:=1 to a do s:=s mod k + v[i] mod k;
     for i:=1 to n-a+1 do
     begin
          sc:=s;
          if s mod k = 0 then inc(nr);
          for j:=i+a to i+b-2 do
          begin
               sc:=sc mod k + v[j] mod k;
               if sc mod k = 0 then inc(nr);
          end;
          s:=s-v[i]mod k+v[i+a]mod k;
     end;
     writeln(g,nr);
     close(g);
end.