fibo

from math import sqrt
from pwn import *
import time

def fib(n):
    return pow(2 << n, n + 1, (4 << 2*n) - (2 << n) - 1) % (2 << n)

# print fib(1)

host = "125.235.240.167"
port = 12345

r = remote(host, port)
r.sendline("1")
time.sleep(0.2)
r.sendline("1")
time.sleep(0.2)
r.sendline("2")
time.sleep(0.2)
r.sendline("3")
time.sleep(0.2)
r.sendline("5")
time.sleep(0.2)

s = "3\n4\n5"
banner = r.recvuntil(s + "\n")
while True:
    # banner = r.recvuntil("\n")
    # r.send('\n')
    data = r.recvline()
    print "data :", data
    if "Goodjob, Here is your flag" in data:
        r.interactive()
    x = int(data)
    payload = str(fib(abs(x)))
    if (x < 0 and x % 2 == 0):
        payload = "-" + payload
    print payload
    r.sendline(payload)
    s = payload[-5:-1] + payload[-1]
    print "s: ", s
    # r.interactive()
r.close()