program main
c This program calculates the variance of the first 10**9 integers
c using both cpus on the dual processor Macintosh.
c To compile with the Absoft Fortran compiler, use:
c f77 -O -Q92 adder.f MacMP.f "{SharedLibraries}"MPLibrary -o adder.out
      implicit none
      integer TickCount
      external TickCount
      integer NINT
      parameter(NINT=1000000000)
      integer n, start
      integer start_program, end_program
      double precision sum1, sum2, mean, mesq
      external adder
      n = NINT
      start = 0
      start_program = TickCount()

      call adder(n,start,sum1,sum2)

      mean = sum1 / n
      mesq = sum2 / n

      write (*,'(i15,1x,f20.3,1x,f21.3)') n, mean, mesq - (mean * mean)

      end_program = TickCount()
      write (*,*)
      write (*,'("time in sec: ",f7.2)') (end_program-start_program)/60.
      write (*,*) 'hit carriage return to quit'
      pause
      stop
      end


      subroutine adder(n,start,s1,s2)
      integer n, start
      double precision s1, s2
      integer i
      double precision ls1, ls2
      ls1 = 0
      ls2 = 0
      do 10 i = start, n-1
      ls1 = ls1 + dble(i)
      ls2 = ls2 + dble(i)*i
   10 continue
      s1 = ls1
      s2 = ls2
      return
      end