#include <sourcemod>
#include <sdkhooks>

new String:weapon[20];

SDKHook(people , SDKHook_WeaponCanUsePost, CanUse_Func);

public Action:CanUse_Func(i, ent)
{
     if (GetClientTeam(i) == 3 || GetEntityClassname(ent, weapon, sizeof(weapon)) && StrEqual(weapon, "weapon_knife"))
     {
         return Plugin_Continue;
     }
     return Plugin_Handled;
}