STACK DATASTRUCTURE

stack = []
MAX_SIZE = 5

def push(p):
    if len(stack)==MAX_SIZE:
        print("overflow")
    else:
        stack.append(p)
    return stack


def pop():
    if len(stack) != 0:
        del stack[-1]
    else:
        print("underflow")
    return (stack)


while True:

    print("1 for push ")
    print("2 for pop ")
    print("3 for exit")
    choice = int(input())
    if choice == 1:
        n = int(input("enter input: "))
        result = push(n)
        print(result)
    elif choice == 2:
        result = pop()
        print(result)
    elif choice == 3:
        break
    else:
        print("wrong choice")