class MinStack(object):
    def __init__(self):
        self.stack = []

    def push(self, val):
        if not self.stack:
            self.stack.append((val, val))
        else:
            mn = min(self.stack[-1][1], val)
            self.stack.append((val, mn))
            # print(self.stack)

    def pop(self):
        if self.stack:
            # print(self.stack)
            self.stack.pop()

    def top(self):
        if self.stack:
            # print(self.stack)
            return self.stack[-1][0]
        return 0

    def getMin(self):
        if self.stack:
            # print(self.stack)
            return self.stack[-1][1]
        return 0
        

minStack = MinStack()
minStack.push(-2)
minStack.push(0)
minStack.push(-3)
minStack.push(4)
minStack.getMin() # return -3
minStack.pop()
minStack.top()    # return 0
minStack.getMin() # return -2



# Your MinStack object will be instantiated and called as such:
# obj = MinStack()
# obj.push(val)
# obj.pop()
# param_3 = obj.top()
# param_4 = obj.getMin()