Help With Address

Hello;
I have found some direct relatives living in the Slovak Republic.I also found their address.I was hoping someone could help me with the proper formatting so I could mail them a letter.I will disguise their name and city to protect their identity.

John Doe Frana Krala 196/19, 05921 Anytown Slovak Republic

Some places I've seen 05921 or 059 21 (with a space between)

I know that the Frana Krala is the street.I'm guessing 196/19 is the house number.I'm not sure if that's a zip code at the end.Do I put a space in it or not?What I would like is for someone to show me exactly how I should address the envelope.
Thank you.
Dan