C this program demonstrate several features of fortran77
C in particular the goto command
C notice how columns are aligned
C23456789012345678901234567890
      program program3


      print*,' hello '  ! write to terminal
      write(6,*)' hello again '  ! this does the same
C comment: now ask for some numbers
  123 continue
      print*,' give me a number '
      print*,' (to end, press ctrl-c) '
      read*,x
      write(6,*)' give me another number '
      read(5,*)y   ! another read to read from terminal
      z = x+y
     & - 1.0       ! an example of continuation on second line
      print*,' z =', z
      goto 123
      end