def balanced_brackets(brac):
    s = Stack()
    brackets = '(' ')' '<' '>'
    while not brac.is_empty():
        a = s.peak(brac)
        if not a == brackets:
            s.pop(a)
        elif a == '(' and ')':
            s.pop(a)
        elif a == '<' and '>':
            s.pop(a)
        else:
            return False