[GRASS-user] Valid format for entering the Central Meridian

Hello
I´m new to Grass and already have a problem when trying to make a new location.
I have all the information i need, but I don´t know how to type it in appropriate.

My Central Meridian is on 13° 20´ E

Grass says:

Enter Central Meridian (96W) :

What do I have to type in? I already tried: 13.20E; 13,20E; 13E20 …

Can´t find anything helpful in the web

regards
Stefan