input: def linearSearch(search_item):
      """
      Perform a linear search on the predefined array to find the position of the search_item.
      
      >>> linearSearch('bookstore')
      2
      >>> linearSearch('park')
      -1
      """
      array = ['school', 'hospital', 'bookstore', 'mall', 'theatre']
      for i in range(len(array)):
          if array[i] == search_item:
              return i
      return -1
output:     array = ['school', 'hospital', 'bookstore', 'mall', 'theatre']
      for i in range(len(array)):
          if array[i] == search_item:
              return i
      return -1