program write_data_i
      character*20 fname
      write(*,*)'Give a file name:(20 chr max)'
      read(*,*)fname

      write(*,*)'How many numbers will you type in?'
      read(*,*)n

      open(unit=10,file=fname)
      write(10,*)n

      do i=1,n
        write(*,*)'Type in one number, please.'
        read(*,*)a
        write(10,*)a
      enddo
      close(10)

      write(*,*)'Your',n,' number(s) has been written into ',fname

      end