class Point
  attr_reader :x, :y

  def initialize(x, y)
    @x = x
    @y = y
  end

  def in?(n)
    0 < @x && @x <= n && 0 < @y && @y <= n
  end

  def left
    Point.new(@x + 1, @y)
  end

  def right
    Point.new(@x - 1, @y)
  end

  def up
    Point.new(@x, @y + 1)
  end

  def down
    Point.new(@x, @y - 1)
  end

  def eql?(other)
    @x == other.x && @y == other.y
  end

  def ==(other)
    eql?(other)
  end

  def hash
    @x + @y * 100
  end
end

n, v, sx, sy, gx, gy = gets.split.map(&:to_i)
map = Hash.new(0)
vmap = Hash.new(-1)
(1..n).each do |y|
  gets.split.map(&:to_i).each.with_index(1) do |l, x|
    map[Point.new(x, y)] = l
  end
end

s = Point.new(sx, sy)
g = Point.new(gx, gy)

count = 0
list = {}
list[s] = v
vmap[s] = v
loop do
  count += 1
  next_list = {}
  list.each do |point, life|
    [point.left, point.right, point.up, point.down].each do |next_point|
      if next_point.in?(n)
        next_life = life - map[next_point]
        if next_life > 0
          if next_point == g
            puts count
            exit
          elsif next_life > vmap[next_point]
            vmap[next_point] = next_life
            next_list[next_point] = next_life
          end
        end
      end
    end
  end
  if next_list.empty?
    break
  end
  list = next_list
end
puts(-1)