def solve(s,a,b)
  if s == 0
    0
  elsif s == 1
    (s - a).abs + 1
  elsif (s - a).abs < (s - b).abs
    (s - a).abs + s
  else
    candiate = [(s-b).abs + (s-1).abs + (a - 1).abs + 1]
    candiate.push((s-b).abs + (s-a).abs + a) if a > 0 
    candiate.min
  end
end

s,a,b = gets.split.map(&:to_i)
puts solve(s,a,b)