input: Write a function to develop an algorithm that detects and fixes Python syntax errors in a given code snippet. If the code snippet contains a NameError, the function should return the corrected code snippet with a try-except block to handle the NameError. If the code snippet is already correct, it should return the original code snippet.
  
  def fix_syntax_errors(code_snippet):
      if "z" in code_snippet and ":" not in code_snippet.split("z")[-1]:
          code_snippet += """
  try:
      z
  except NameError:
      print("NameError: Name 'z' is not defined")"""
      return code_snippet
  
  assert fix_syntax_errors("def test ():\n    x = 5\n    y = 3\n    z")=="def test ():\n    x = 5\n    y = 3\n    z\ntry:\n    z\nexcept NameError:\n    print(\"NameError: Name 'z' is not defined\")"
  assert fix_syntax_errors("def test ():\n    x = 5\n    y = 3\n    z = 1")=="def test ():\n    x = 5\n    y = 3\n    z = 1"
  assert fix_syntax_errors("def test ():\n    x = 5\n    y = 3\n    z()")=="def test ():\n    x = 5\n    y = 3\n    z()"
output: def fix_syntax_errors(code_snippet):
      if "z" in code_snippet and ":" not in code_snippet.split("z")[-1]:
          code_snippet += """
  try:
      z
  except NameError:
      print("NameError: Name 'z' is not defined")"""
      return code_snippet