input: Write a Python function to print "Hello World!" and the results of a simple math operation.
  assert print_hello_and_math() == "Hello World!\n50"
  assert print_hello_and_math() == "Hello World!\n50"
  assert print_hello_and_math() == "Hello World!\n50"
output: def print_hello_and_math():
      return "Hello World!\n" + str(45 + 5)