c-----------------------------------------------------------
c     Less-commented (i.e. more reasonable level of 
c     comments) version of mysum.
c-----------------------------------------------------------
c     mysum_s:  reads numbers one per line from stdin
c     and writes sum on stdout.  Ignores invalid inputs
c     but counts number encountered and reports on stderr.
c-----------------------------------------------------------
      program      mysum

      implicit     none

      real*8       vi,         sum
      integer      rc,         nbad

      nbad = 0
      sum  = 0.0d0

 100  continue
         read(*,*,iostat=rc,end=200)  vi
         if( rc .eq. 0 ) then
            sum = sum + vi
         else 
            nbad = nbad + 1
         end if
      go to 100
 200  continue

      write(*,*) sum

      if( nbad .gt. 0 ) then
         write(0,*) nbad, ' invalid inputs'
      end if

      stop

      end