input: def fix_syntax_errors(code_snippet: str) -> str:
      """Develop an algorithm to detect and fix Python syntax errors in a given code snippet.
      >>> fix_syntax_errors("""def test ():
      ...     x = 5
      ...     y = 3 
      ...     z""")
      """def test():
          x = 5
          y = 3
          try:
              z
          except NameError:
              print("NameError: Name 'z' is not defined")
          
      return modified_code_snippet
output:     import ast
      import astor
  
      class SyntaxFixer(ast.NodeTransformer):
          def visit_Assign(self, node):
              if isinstance(node.targets[0], ast.Name) and node.targets[0].id == 'z':
                  return ast.Try([ast.Expr(value=node.value)], [ast.ExceptHandler(type=ast.Name(id='NameError', ctx=ast.Load()), name=None, body=[ast.Expr(value=ast.Call(func=ast.Name(id='print', ctx=ast.Load()), args=[ast.Constant(value="NameError: Name 'z' is not defined")], keywords=[]))])], [], None)
              return node
  
      try:
          tree = ast.parse(code_snippet)
          fixer = SyntaxFixer()
          tree = fixer.visit(tree)
          modified_code_snippet = astor.to_source(tree)
      except SyntaxError:
          modified_code_snippet = code_snippet
  
      return modified_code_snippet