PROGRAM SN
C     this program divides a spectrum
      character*80 s80
      real*8 x,y
      open(9,file='S.PRN')
      open(10,file='SN.PRN')
      call getarg(1,s80)
      read(s80,*)n
1     read(9,*,end=99,err=99)x,y
      write(10,100)x,y/dble(n)
100   format(f12.2,f25.12)
      goto 1
99    close(9)
      close(10)
      stop
      end