Ah, gets ko na. So a private key in decimal format would be just a really large number. Something like:

1234567890123456789012345678901234567890

Yung sa hex format naman, it's similar to the direct private key I gave earlier but using hexadecimal characters (0-9 and A-F). So something like:

E9873D79C6D87DC0FB6A5778633389F4453213303DA61F20BD67FC233AA33262

Pero remember ha, these are just examples. Never share your real private keys!