The dibromide shown has unspecified configuration at both stereocentres, i.e. it is the mixture of all its stereoisomers. It reacts completely with excess $\mathrm{NaCN}$ in DMF, with $\mathrm{S}{}_{\mathrm{N}}2$ inversion at each carbon bearing Br. Count every configurational stereoisomer (optical isomers counted separately; a meso form counts once) of the dinitrile product constitution that is obtained from this mixture. Give your answer as an integer.

Numerical answer type, tolerance 0.5.