class myStack:

    myList = list()

    def __init__(self):
        self.myList = list()


    def push(self, Object):
        self.myList.append(Object)

    def pop(self):
        return self.myList.pop(len(self.myList)-1)

    def peek(self):
        return self.myList[0]

    def isEmpty(self):
        if len(self.myList) == 0:
            return True
        else:
            return False


def validatebrackets(iisstring):
    stack = myStack()
    for letter in iisstring:
        if letter == '(' or letter == '[' or letter == '<':
            stack.push(letter)
        elif letter == ')' or letter == ']' or letter == '>':
            popedbracket = stack.pop()
            if letter == ')' and popedbracket != '(' or letter == '>' and popedbracket != '<' or letter == ']' and popedbracket != '[':
                raise Exception('wrong bracket')
    return "succeed"

def mybin(number):
    string = ""
    if number == 0 or number == 1:
        return str(number)
    string += mybin(int(number/2))
    string += str(number % 2)

    return string