One needs as many 105mm lenses as necessary
For me, that is a pretty substantial number
Most of them are 105/2.5 versions (S- and F-mount), plus various f/2.8 and f/4 Micro-Nikkors, Bellows-Nikkors, the tiny 10.5cm f/4 T, the mighty 105/1.4 AFS, and of course the 105/4.5 UV-Nikkors.