class Yukicoder
  def initialize
    a, b, s = gets.chomp.split(' ').map(&:to_i)

    if (a - s).abs <= (b - s).abs
      puts (a - s).abs + s
    else
      if s == 1
        puts (a - s).abs + s
      else
        dist1 = (b - s).abs + (s - 1) + (a - 1).abs + 1
        dist2 = (b - s).abs + (a - s).abs + a + (a.zero? ? 1 : 0)

        puts [dist1, dist2].min
      end
    end
  end
end

Yukicoder.new