Identify the Lewis acid in this balanced equation:

Central N is bonded above, left, and below to C H 3 and has 2 electron dots to the right. Plus. B is bonded above, below left, and below right to H. right arrow. N superscript plus is bonded above, below, and left to C H 3, and to the right to B; the B is bonded above, below and right to H.