input: from typing import List
  
  def create_binary_strings_without_consecutive_zeros(n: int) -> List[str]:
      """
      Given a positive integer n.
  
      A binary string is considered valid if every substring of length 2 includes at least one "1".
  
      Return any order of all valid strings of length n.
  
      Examples:
      >>> n = 3
      ['010','011','101','110','111']
      >>> n = 1
      ['0','1']
  
      Constraints:
      1 <= n <= 18
      """
output:     
      if n == 1:
          return ['0', '1']
      
      result = []
  
      def backtrack(current):
          if len(current) == n:
              result.append(current)
              return
          if len(current) == 0 or current[-1] == '1':
              backtrack(current + '0')
          backtrack(current + '1')
  
      backtrack("")
      return result
  