Design a Stack With Increment Operation.py

class CustomStack:

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

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

    def pop(self) -> int:
        return self.stack.pop() if len(self.stack) > 0 else -1

    def increment(self, k: int, val: int) -> None:        
        l = k if len(self.stack) > k else len(self.stack)
        for i in range(l):
            self.stack[i] += val