def solve(x, y, d)
  z = [x.abs, y.abs].max
  if z.zero?
    0
  elsif z < d
    2
  elsif z == d
    1
  else
    (z - 1) / d + 1
  end
end

_ = gets.to_i
ds = gets.chomp.split.map(&:to_i)
d = ds.max
x, y = gets.chomp.split.map(&:to_i)
p solve(x, y, d)