program day5_fortran
    integer :: INPUT_FD
    integer :: io_status
    integer :: read_status
    integer :: read_value
    logical :: file_exists

    INPUT_FD = 9
    io_status = 42
    read_value = -1
    file_exists = 1
    read_status = 42

    inquire(file = "input.txt", exist = file_exists)
    open(unit = INPUT_FD, file = "input.txt", iostat = io_status, action = 'read')

    write(*, *) file_exists

    read(INPUT_FD, '(i1)', iostat = read_status) read_value

    write(*, *) "Hello, World!"
    write(*, *) io_status
    write(*, *) read_status
    write(*, *) read_value
end program