input: 
  def VersionControl(lines):
      """ Implement a basic version control system in Python that keeps track of changes in the code.
      
      This class allows you to commit changes and restore to previous versions of the code stored in a log file.
      Example:
      for vc = VersionControl([1, 2, 3])
      vc.commit()  # Commits the current state and logs it
      vc.lines = [4, 5, 6]
      vc.commit()  # Commits the new state
      vc.restore()  # Restores to the previous state
      
      """
      def __init__(self, lines):
          self.lines = lines
          self.mark = 0
   
      def commit(self):
          self.mark += 1
          log_file = open("log_file.txt", "a+")
          log_file.write(str(self.mark) + ": " + str(self.lines))
          log_file.close()
   
      def restore(self):
          log_file = open("log_file.txt", "r")
          lines = log_file.readlines()
          to_mark = self.mark-1
   
          self.lines = lines[to_mark]
          log_file.close()
  
output:     def restore(self):
          log_file = open("log_file.txt", "r")
          lines = log_file.readlines()
          to_mark = self.mark - 1
          if to_mark >= 0:
              self.lines = eval(lines[to_mark].split(": ")[1])
              self.mark = to_mark
          log_file.close()