Coordination Compounds · Isomerism in coordination compounds

X is the number of geometrical isomers exhibited by $\ce{[Pt(NH3)(H2O)BrCl]}$.

Y is the number of optically inactive isomer(s) exhibited by $\ce{[CrCl2(ox)2]^{3-}}$

Z is the number of geometrical isomers exhibited by $\ce{[Co(NH3)3(NO2)3]}$

The value of X + Y + Z is .