The number of molecules/ion/s having trigonal bipyramidal shape is _______. \( \mathrm{PF_5} \), \( \mathrm{BrF_5} \), \( \mathrm{PCl_5} \), \( [\mathrm{Pt\!Cl_4}]^{2-} \), \( \mathrm{BF_3} \), \( \mathrm{Fe(CO)_5} \)