The nettle-like one
No interactions present.
Probably a Mentha.
Short of having experience/a flora of Serbia, it is probably futile trying to ID to species. There are likely to be different species of Ballota, Lamium and so on compared to here.
I suggest you save up and buy the 10 volume...
“Flora of Serbia” (Josifović, 1970-1976; 1977; Sarić and Diklić, 1986)
My Flickr photos...
Lat/Lng: 43.7932, 19.5153