input: from typing import List
  
  def concatenate_strings(strings: List[str]) -> str:
      """ Concatenate a list of strings with a space in between each string.
      >>> concatenate_strings(["Hello", "World"])
      'Hello World'
      """
      return ' '.join(strings)
output:     
      result = ""
      for s in strings:
          result += s + " "
      return result.strip()
  