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

# m = 20
# M = 2 * m + 1
# d = 4
# f = [nil] * M
# inf = 1000000000
# M.times{|i| f[i] = [inf] * M}
#
# f[m][m] = 0
# stack = [[m, m]]
#
# while not stack.empty?
#   x, y = stack.pop
#   (-d..d).each do |i|
#     (-d..d).each do |j|
#       next if i.abs != d && j.abs != d
#       x2 = x + i
#       y2 = y + j
#       next if x2 < -m || y2 < -m || x2 > 2*m || y2 > 2*m
#       if f[x2][y2] > f[x][y] + 1
#         f[x2][y2] = f[x][y] + 1
#         stack.push [x2, y2]
#       end
#     end
#   end
# end
#
#
# M.times do |i|
#   M.times do |j|
#     v = f[i][j]
#     if v.zero?
#       STDOUT.write sprintf "\e[31m%03d\e[0m ", v
#     elsif v.even?
#       STDOUT.write sprintf "\e[32m%03d\e[0m ", v
#     else
#       STDOUT.write sprintf "%03d ", v
#     end
#   end
#   puts ""
# end

_ = gets.to_i
ds = gets.chomp.split.map(&:to_i)
x, y = gets.chomp.split.map(&:to_i)
p ds.map {|d| solve(x, y, d)}.min