You are given a map of letters in the form of an array of arrays. Your task is to determine whether it’s possible to make a word using this map.

The word can be built only from letters that are adjacent to each other in this map. Also, these letters must go in the order in which they go in the same given map. To make a desired word each character can be used only once.

Input: Two arguments. The first one is the map of letters in the form of an array of arrays. The second is the word we are looking for.

Output: Boolean. Is it possible to make a word using this map?

Example:

word_search([['A', 'B', 'C', 'D'],
  ['E', 'F', 'G', 'H'],
  ['I', 'J', 'K', 'L']],
 'BAEF') == True
word_search([['A', 'B', 'C', 'D'],
  ['E', 'F', 'G', 'H'],
  ['I', 'J', 'K', 'L']],
 'ABCDE') == False