Rating:

```
n: 2174096211032823084932239036566496093206280423
```

In the factory.txt file, there were prime numbers that might be in the database.
I programmed a python code to get prime numbers from the database.

```python
import requests
from bs4 import BeautifulSoup
n = open("factory.txt").read().split()[1]

html = requests.get("http://factordb.com/index.php?query="+n).text
html = BeautifulSoup(html,"html.parser").find_all("font")
small_num = html[1].string
big_num = html[2].string

flag = "KCTF{" + small_num + "-" + big_num + "}"
print(flag)
```

FLAG : ```KCTF{39434538531451803895327-55131777675015246472249}```