Find the total number of compounds having equal all bond Lenbrths equal :

$\begin{array}{l}{\mathrm{PCl}}_5,{\mathrm{PF}}_5,{\mathrm{SF}}_4,{\mathrm{XeF}}_2,{\mathrm{XeF}}_4,{\mathrm{XeF}}_7,{\mathrm{SF}}_6,{\mathrm{ClF}}_3,{\mathrm{BrF}}_5\text{, }\\ \mathrm{Ni}(\mathrm{CO}{)}_4,{\mathrm{IF}}_7\end{array}$