From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00
	autolearn=unavailable autolearn_force=no version=3.4.4
Path: 
 eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!news.eternal-september.org!feeder.eternal-september.org!weretis.net!feeder4.news.weretis.net!newsreader4.netcologne.de!news.netcologne.de!.POSTED.xdsl-213-196-221-111.netcologne.de!not-for-mail
From: Frank Buss <fb@frank-buss.de>
Newsgroups: comp.lang.ada
Subject: quiz for Sequential_IO Read
Date: Sun, 3 Sep 2017 13:01:25 +0200
Organization: news.netcologne.de
Distribution: world
Message-ID: <oogne5$94b$1@newsreader4.netcologne.de>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Sun, 3 Sep 2017 11:01:25 +0000 (UTC)
Injection-Info: newsreader4.netcologne.de;
 posting-host="xdsl-213-196-221-111.netcologne.de:213.196.221.111";
	logging-data="9355"; mail-complaints-to="abuse@netcologne.de"
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.0
X-Mozilla-News-Host: news://news.netcologne.de:119
Xref: news.eternal-september.org comp.lang.ada:47906
Date: 2017-09-03T13:01:25+02:00
List-Id: <comp.lang.ada>

What does this program output?


with Ada.Sequential_IO;
with Ada.Text_IO; use Ada.Text_IO;

procedure Hello is

    type Byte is range 0..255;

    package Byte_IO is new Ada.Sequential_IO(Byte);
    A : Byte;
    B : Byte;
    C : Byte;
    File : Byte_IO.File_Type;

begin
    Byte_IO.Open(File, Byte_IO.In_File, "test.txt");
    Byte_IO.Read(File, A);
    Put_Line(Byte'Image(A));
    Byte_IO.Read(File, B);
    Put_Line(Byte'Image(B));
    C := (A mod 2) + (B mod 2);
    Put_Line(Byte'Image(C));
    Byte_IO.Close(File);
end;


The content of test.txt is just the ASCII string "hello":

hexdump -C test.txt:
00000000  68 65 6c 6c 6f                                    |hello|
00000005

Answer without compiling and running it! A hex calculator is allowed. 
Extra brownie point if you can explain the result :-)

Don't know if it matters, compiled with "gnatgcc (Debian 6.3.0-18) 6.3.0 
20170516", 64 bit version, and "-g -O2" command line options.

-- 
Frank Buss, http://www.frank-buss.de
electronics and more: http://www.youtube.com/user/frankbuss