Part 1+2

Sorry to be so late. I have to admit that I finished it after the
deadline because of some foolish things, and I didn't upload it because
I
forgot to recharge my vpn while my roommates had fallen asleep and had
to
send it to Yilong Gu in other place the next morning, and finally I
forgot to upload it to the hub......It's all my fault, and thank Gu for
forgiving me and
thank our leader for reminding me......