import Data.List as List
import Data.Char as Char

main = do
 putStrLn("Hello")

issorted :: [Int] -> Bool
issorted xs = and $ zipWith(<=) xs (tail xs)

digits :: Int -> [Int]
digits = map Char.digitToInt . show

hasAdjacentPair :: [Int] -> Bool
hasAdjacentPair n = (maximum (map length (List.group n))) >= 2

hasAdjacentPairb :: [Int] -> Bool
hasAdjacentPairb n = elem 2 (map length (List.group n))

day4a :: Int -> Bool
day4a n =(hasAdjacentPair $ digits n) && ( issorted $ digits n )

day4b :: Int -> Bool
day4b n =(hasAdjacentPairb $ digits n) && ( issorted $ digits n )

filterDay4a :: [Int] -> [Int]
filterDay4a ns = filter(\n-> day4a n) ns

filterDay4b :: [Int] -> [Int]
filterDay4b ns = filter(\n-> day4b n) ns