input: def concatenate_and_print_strings():
      """
      Create a Python program to store the strings "Hello" and "World" and print them in the same line separated by a space.
      >>> concatenate_and_print_strings()
      Hello World
      """
      string1 = "Hello"
      string2 = "World"
      print(string1 + " " + string2)
output:     string1 = "Hello"
      string2 = "World"
      print(string1 + " " + string2)