quiz for Sequential_IO Read

[Frank Buss <fb@frank-buss.de>]

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