\( X \) is the number of geometrical isomers exhibited by \( [\mathrm{Pt(NH_3)(H_2O)BrCl}] \).
\( Y \) is the number of optically inactive isomer(s) exhibited by \( [\mathrm{CrCl_2(ox)_2}]^{3-} \).
\( Z \) is the number of geometrical isomers exhibited by \( [\mathrm{Co(NH_3)_3(NO_2)_3}] \).
The value of \( X + Y + Z \) is ____________.