#!/usr/bin/python
#encoding:utf8
import random
import sys
from binascii import hexlify, unhexlify

def GF2_add(p1, p2):
    assert(p1>=0 and p2>=0)
    return p1 ^ p2

def GF2_mod(p, mod):
    assert(p>=0 and mod>0)
    while p.bit_length() >= mod.bit_length():
        mask = mod << (p.bit_length() - mod.bit_length())
        p ^= mask
    return p

def GF2_mul_mod(p1, p2, mod):
    assert(p1>=0 and p2>=0 and mod>0)
    r=0
    while p2:
        if p2 & 1:
            r ^= p1
        p2 >>= 1
        p1 = GF2_mod(p1<<1, mod)
    return r

def GF2_pow_mod(b, e, mod):
    assert(b>=0 and e>=0 and mod>0)
    r=1
    while e:
        if e&1:
            r = GF2_mul_mod(r, b, mod)
        e >>= 1
        b = GF2_mul_mod(b,b,mod)
    return r

if __name__=="__main__":
    if len(sys.argv)!=2:
        print ("Usage: {0} exposant_privé".format(sys.argv[0]))
        sys.exit(1)
    D = int(sys.argv[1],0)
    N = 231002291543555016818569199325004102033150445385414455365880736176436715311790663130589862191084808106664722172105531887027184495017140783502576089624623090612010946552911266876786591303954740526520748757324542859056473246482362113968367791176213289397973534046005478174177408900797351038135732809112135056071
    #à refaire avec E=3 ou 65537 (plus logique, même si cette version est solvable)
    E = 65533
    test_plain = random.randrange(2**1024)
    test_crypt = GF2_pow_mod(test_plain, E, N)
    if GF2_pow_mod(test_crypt, D, N)==test_plain:
        flag = 3084449846433041813390375663058703285782448134840024007803494551180465048150640197025779798034586128810372902144370282944067512576975973977099499869946999914888177281161149730177343199310024653678751046701545038089863997906852127878655263416175563754210990106963126850755139552152622891343746619023468031658
        flag = GF2_pow_mod(flag,D,N)
        flag = unhexlify(hex(flag)[2:].strip("L").zfill(256)).decode()
        flag = flag[:ord(flag[-1])]
        print (flag)
    else:
        print ("Non.")