class Register:
    registers = []

    def __init__(self, n_bits, name=None):
        self.n_bits = n_bits
        if name is None:
            self.name = "r{}".format(len(Register.registers))
        else:
            self.name = name
        self.value = 0
        Register.registers.append(self)

    def truncate_val(self, value, bits=None):
        if bits is None:
            bits = self.n_bits
        return value & ((1 << bits) - 1)

    def trucate(self):
        self.value = self.truncate_val(self.value)

    def set(self, value):
        if value < 0:
            self.value = self.truncate_val(abs(value), self.n_bits - 1)
            self.negate()
        self.trucate()

    def get(self):
        return self.value

    def get_signed(self):
        if self.value & (1 << (self.n_bits - 1)) == 0:
            return self.value
        else:
            return self.value - (1 << self.n_bits)

    def complement(self):
        self.value = self.value ^ ((1 << self.n_bits) - 1)

    def negate(self):
        self.complement()
        self.value += 1


class Acumulator(Register):
    positive_flag = False
    negative_flag = False
    zero_flag = False
    carry = False

    def add(self, register):
        pass