import Data.List.Split (splitOn)

winsFromTimeDist :: (Int, Int) -> Int
winsFromTimeDist (time, dist) = length $ filter (> dist) $ zipWith (*) [0..time] (reverse [0..time])

main :: IO ()
main = do
  lines <- lines <$> getContents

  -- let values = map (map (\y -> read y :: Int) . splitOn [' '] . drop 9) lines
  let values = map (read . filter (/= ' ') .  drop 9) lines :: [Int]
  let wins = winsFromTimeDist (values!!0, values!!1)

  print wins