c----------------------------------------------
c      backgrd4.f
c    
c      subrtn file : pk1subrtn
c       
c----------------------------------------------
c      main program   backgrd4.f    << daytime >>
       parameter (n=10,n1=n-1,rd=1.571/n1,n2=n/2)
c
       call initvrml
c
       call backd(n1,n2,rd)
c
       stop
       end
