每条指令单独验一遍

运行下面这段程序，填写它打印出来的结果。

PROG = [0b00001001, 0b01000111, 0b10000011, 0b11000000]

def decode(w):
    return (w >> 6) & 3, (w >> 5) & 1, w & 31

def step(R0, w):
    op, rd, imm = decode(w)
    if op == 0:
        return imm
    if op == 1:
        return (R0 + imm) & 255
    if op == 2:
        return (R0 - imm) & 255
    return R0

print("/".join(str(step(9, w)) for w in PROG))