import Data.Array
 
memoized_binomial :: Integer -> Integer -> Integer
memoized_binomial a b = arr ! (a, b) where
  arr = array ((0, 0), (size, size)) [((x, y), inner (x, y) size) | x <- [0..size], y <- [0..size]] 
    where inner (x, y) size
            | x == 0 && y == 0 = 0
            | x == 0 || y == 0 = 1
            | otherwise = arr ! (x - 1, y) + arr ! (x, y - 1)
          size = max a b
 
main = putStrLn $ show $ memoized_binomial 800 800

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