human
I found an interesting problem on https://leetcode.com/problems/design-a-stack-with-increment-operation/:
Design a stack which supports the following operations.
Implement the CustomStack class:

CustomStack(int maxSize) Initializes the object with maxSize which is the maximum number of elements in the stack or do nothing if the stack reached the maxSize.
void push(int x) Adds x to the top of the stack if the stack hasn't reached the maxSize.
int pop() Pops and returns the top of stack or -1 if the stack is empty.
void inc(int k, int val) Increments the bottom k elements of the stack by val. If there are less than k elements in the stack, just increment all the elements in the stack.

 
Example 1:
Input
["CustomStack","push","push","pop","push","push","push","increment","increment","pop","pop","pop","pop"]
[[3],[1],[2],[],[2],[3],[4],[5,100],[2,100],[],[],[],[]]
Output
[null,null,null,2,null,null,null,null,null,103,202,201,-1]
Explanation
CustomStack customStack = new CustomStack(3).
// Stack is Empty []
customStack.push(1).
                         // stack becomes [1]
customStack.push(2).
                         // stack becomes [1, 2]
customStack.pop().
                           // return 2 --> Return top of the stack 2, stack becomes [1]
customStack.push(2).
                         // stack becomes [1, 2]
customStack.push(3).
                         // stack becomes [1, 2, 3]
customStack.push(4).
                         // stack still [1, 2, 3], Don't add another elements as size is 4
customStack.increment(5, 100).
               // stack becomes [101, 102, 103]
customStack.increment(2, 100).
               // stack becomes [201, 202, 103]
customStack.pop().
                           // return 103 --> Return top of the stack 103, stack becomes [201, 202]
customStack.pop().
                           // return 202 --> Return top of the stack 102, stack becomes [201]
customStack.pop().
                           // return 201 --> Return top of the stack 101, stack becomes []
customStack.pop().
                           // return -1 --> Stack is empty return -1.

 
Constraints:

1 <= maxSize <= 1000
1 <=...

I tried it in Python, but could not do it. Can you solve it?
assistant
#Here is the Python program you requested.

class CustomStack:

    def __init__(self, maxSize: int):
        self.maxSize = maxSize
        self.stack = []
        self.incre = []

    def push(self, x: int) -> None:
        if len(self.stack) < self.maxSize:
            self.stack.append(x)
            self.incre.append(0)

    def pop(self) -> int:
        if self.stack:
            if len(self.incre) > 1:
                self.incre[-2] += self.incre[-1]
            return self.stack.pop() + self.incre.pop()
        else:
            return -1

    def increment(self, k: int, val: int) -> None:
        if self.incre:
            self.incre[min(len(self.incre), k)-1] += val

# Your CustomStack object will be instantiated and called as such:
# obj = CustomStack(maxSize)
# obj.push(x)
# param_2 = obj.pop()
# obj.increment(k,val)