Hash of a .pdf file

[redcat]

Hi everybody, I'm trying to find the password of a .pdf file.
So I use the python script to obtain the hash. This is an extract of the result :

Code:

$pdf$2*3*128*-3904*1*16*...*32*...

When I search what hash I need to enter for PDF, I've seen one which is pretty similar :

-m 10500 PDF 1.4 - 1.6 (Acrobat 5 - 8)

with this example on the wiki :

Code:

$pdf$2*3*128*-1028*1*16*da42ee15d4b3e08fe5b9ecea0e02ad0f*32*...*32*...

So I see that mine have 3904 instead of the 1028 on the example. What means this numbers ? Can I still use  the -m 10500 or it's useless and I need to use another hash method ?

Regards.