a,b,s = gets.split.map(&:to_i)
if s == 1
    p (a - s).abs + 1
elsif (a - s).abs <= (b - s).abs
    p (a - s).abs + s
else
    p (b - s).abs + [s - 1, (a - s).abs].min + (a - 1).abs + 1
end