new_contents: class MinStack:
      # @param x, an integer
      
      def __init__(self):
          self.stack = []
          self.min_stack = []
          
      # @return an integer
      def push(self, x):
          self.stack.append(x)
          
          if len(self.min_stack) == 0 or self.min_stack[-1] >= x:
              self.min_stack.append(x)
          
  
      # @return nothing
      def pop(self):
          num = self.stack.pop(-1)
          if self.min_stack[-1] == num:
              self.min_stack.pop(-1)
              
      # @return an integer
      def top(self):
          return self.stack[-1]
          
      # @return an integer
      def getMin(self):
          return self.min_stack[-1]
  
subject: Create MinStack_001.py