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module Main where
main :: IO ()
main = do
n <- lines <$> readFile "input/03"
print $ countTrees 3 1 n
print $ product [ countTrees 1 1 n
, countTrees 3 1 n
, countTrees 5 1 n
, countTrees 7 1 n
, countTrees 1 2 n
]
countTrees :: Int -> Int -> [String] -> Int
countTrees right down ls = go (map cycle ls)
where go [] = 0
go remaining@(r:rs) = i (head r) + go (map (drop right) (drop down remaining))
where i = fromEnum . (== '#')
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