{$APPTYPE CONSOLE}
{$R-,Q-,O+}

uses
  SysUtils, Math;

const
  eps = 1e-9;

var
  w, n, m, i, j, l, r, mid, ans, k, ans2, x, q, ll, rr, m1, m2: integer;
  a, b: array[0..200001]of extended;
  s, len: extended;

function dist(x1, y1, x2, y2: extended): extended;
begin
  result := sqrt( (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2) );
end;

function f(k: integer): integer;
begin
  s := dist(a[i], w, b[j], 0) + a[k] - a[i];

  l := j;
  r := m + 1;
  while (r - l) > 1 do begin
    mid := (r + l) div 2;
    if len + eps >= (s + b[mid] - b[j] + dist(a[k], w, b[mid], 0)) then
      l := mid
    else
      r := mid;
  end;

  mid := l;
  if len + eps >= (s + b[mid] - b[j] + dist(a[k], w, b[mid], 0)) then
    result := k - i + 1 + mid - j + 1
  else
    result := 0;
end;

begin
  {reset(input, 'birch.in');
  rewrite(output, 'birch.out');}

  read(len, w);

  read(n);
  for i := 1 to n do
    read(a[i]);

  read(m);
  for i := 1 to m do
    read(b[i]);

  ans := 0;

  for i := 1 to n do
    for j := 1 to m do begin
      ll := i;
      rr := n + 2;

      while (rr - ll) > 2 do begin
        m1 := ll + (rr - ll) div 3;
        m2 := rr - (rr - ll) div 3;

        if f(m1) >= f(m2) then
          rr := m2
        else
          ll := m1;

      end;

      ans := max(ans, f(ll));
      ans := max(ans, f(min(ll + 1, n)));
      
      if ans = n + m then begin
        write(ans);
        exit;
      end;

   end;

   write(ans);


end.