The number of species having a square planar shape from the following is __________ .
\( \mathrm{XeF_4}, \, \mathrm{SF_4}, \, \mathrm{SiF_4}, \, \mathrm{BF_4^-}, \, \mathrm{BrF_4^-}, \, [\mathrm{Cu(NH_3)_4}]^{2+}, \, [\mathrm{FeCl_4}]^{2-}, \, [\mathrm{PtCl_4}]^{2-} \)
