class insn_mem:
    memory = [8 * '0'] * 4 * 1024 * 1024

    def __init__(self) -> None:
        pass

    def fetch(self, address):
        insn = self.memory[address + 3] + self.memory[address + 2] + \
               self.memory[address + 1] + self.memory[address]
        return insn