program ch1103
implicit none
integer, dimension (10) :: a = (/ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 /)
integer :: io_stat_number = 0
integer :: i

  open (unit=1,file='data.txt',status='old')
  do i = 1, 10
    read (unit=1,fmt=10,iostat=io_stat_number) a(i)
10  format (i3)
    if (io_stat_number==0) then
      cycle
    else if (io_stat_number==-1) then
      print *, ' end of file detected at line ', i
      print *, ' please check data file'
      exit
    else if (io_stat_number>0) then
      print *, ' non numeric data at line ', i
      print *, ' please correct data file'
      exit
    end if
  end do
  do i = 1, 10
    print *, ' I = ', i, ' a(i) = ', a(i)
  end do
end program ch1103