f :: Int -> Int -> Int -> Int
f a b 1 = abs(a-1) + abs(1-0)
f a b s = do
	if abs(a-s) <= abs(b-s)
		then abs(a-s) + abs(s-0)
		else if a>0
			then min ( abs(b-s) + abs(a-s) + (f a a a) ) ( abs(s-b) + abs(s-1) + (f a 1 1) )
			else abs(s-b) + abs(s-1) + (f a 1 1)

main = do
	[a,b,s] <- (map read . words) `fmap` getLine
	putStrLn $ show $ f a b s