program ch1102
implicit none
integer :: io_stat_number = -1
integer :: i

  do
    print *, 'input integer i:'
    read (unit=*,fmt=10,iostat=io_stat_number) i
10  format (i3)
    print *, ' iostat=', io_stat_number
    if (io_stat_number==0) exit
  end do
  print *, 'i = ', i, ' read successfully'
end program ch1102