import requests

import base64
flag =""
for i in range(2,22):
    r = requests.post('http://167.88.114.217/concavang.php?phieulang=quynhnhu&quynhnhu=thebest&r='+str(i), data = {'lolololo':'lolololo'})
    print base64.b64decode(r.text)
    flag=flag+ base64.b64decode(r.text)[14]
print flag