Among $\mathrm{CrO}, \mathrm{Cr}_2 \mathrm{O}_3$ and $\mathrm{CrO}_3$, the sum of spin-only magnetic moment values of basic and amphoteric oxides is _________ $10^{-2} \mathrm{BM}$ (nearest integer).

(Given atomic number of $\mathrm{Cr}$ is 24 )