Solve script:

import pwn

p = pwn.remote("167.71.143.44", "31273")
p.sendline("1")
for i in range(100):
    print(i)
    p.recv()
    p.sendline("rockpaperscissors")
p.interactive()

The challenge server only checked for the existence of the solution in our input string, so we could pass all three solutions at once.

For full details, see the video writeup here: https://www.youtube.com/watch?v=rCzmJchv8RI