import Data.List

kadomatsu :: [Int] -> Int
kadomatsu [x,y] = 0
kadomatsu (x:y:z:ts) = f + kadomatsu (y:z:ts) where
    f   | isKadomatsu && (maximum [x,y,z] == y || minimum [x,y,z] == y) = 1
        | otherwise = 0
    isKadomatsu = (x /= y) && (x /= z) && (y /= z)

main = do
    getLine
    ts <- map read . words <$> getLine
    print $ kadomatsu ts