startsWithZeros :: ByteString -> Bool
startsWithZeros b = zeros `BS.isPrefixOf` b && ((BS.index b 2) < 16)
  where
    zeros = BS.pack [0, 0]

-- All base16 representations of hashes whose first 5 characters are '0'
startsWithZeros :: ByteString -> Bool
startsWithZeros b = zeros `BS.isPrefixOf` b && ((BS.index b 2) < 16)
  where
    zeros = BS.pack [0, 0]

-- All base16 representations of hashes whose first 5 characters are '0'
startsWithZeros b = zeros `BS.isPrefixOf` b && ((BS.index b 2) < 16)
  where
    zeros = BS.pack [0, 0]

-- All base16 representations of hashes whose first 5 characters are '0'