main = do
  [a, b, c] <- map (read :: String -> Integer) . words <$> getLine
  putStrLn $ show (f a b c)

f :: Integer -> Integer -> Integer -> Integer
f a b c
    | c >=  a && c >=  b  = c - 2 
    | c < a && c < b      = c
    | otherwise           = c - 1