main = do
  [n, k] <- map read . words <$> getLine :: IO [Integer]
  print $ solve n n k

solve :: Integer -> Integer -> Integer -> Integer

solve 0 n k = if k == 0 then (-10) else 0
solve i n k = res + solve (i-1) n k
  where
    res = (max 0 ((div n i) * (i - k))) + max 0 ((mod n i) - k + 1)