Обьяснить программу

program Zachetka;
uses crt;
function CountWord(const aStr : String) : Word;
const
Delims = [' ', '.', ',', ':', ';', '!', '?', '-'];
var
i : Integer;
StrWord : String;
Res : Word;
begin
clrscr;
Res := 0;
StrWord := '';
for i := 1 to Length(aStr) do begin
if not (aStr[i] in Delims) then StrWord := StrWord + aStr[i];
if ( (aStr[i] in Delims) or (i = Length(aStr)) ) and (StrWord <> '') then begin
if UpCase(StrWord[1]) = UpCase( StrWord[ Length(StrWord) ] ) then Inc(Res);
StrWord := '';
end;
end;
CountWord := Res;
end;
const
FileName = 'text.txt';
var
F:Text;
StrTmp : String;
CntWord : Word;
begin
Assign(F, 'D:\text.txt');
Reset(F);
while not Eof(F) do begin
Readln(F, StrTmp);
Writeln(StrTmp);
end;
Reset(F);
CntWord := 0;
while not Eof(F) do begin
Readln(F, StrTmp);
CntWord := CntWord + CountWord(StrTmp);
end;
Close(F);
Writeln('KoJIu4ecTBo CJIoB c oguHakoBou 6ykBou B Ha4aJIe u B KoHLLe= ', CntWord);
end.