d =: ([;._2) 1!:1<'day11'
neigh =: '#'&= -~ [: +/"1 [: +/"2 '#' = 3 3 >;._3 '.'&([,[,~[,.[,.~])
step =: '.L#' {~ ([: -(3<[)*'#'=]) + (2*'#'=]) + ((0=[) * 'L'=]) + 'L'=]
+/,'#'=(neigh step ])^:_ d  NB. 2324
NB. part2 TBD