procedure readSubscribers(var RequiredSubscriber: TRequiredSubscriber);
var
    SourceFile: TBinaryFile;
    TelephoneNumberArray: TTelephoneNumber;
    SurnameArray: TSurname;
    NameArray: TName;
    PatromynicArray: TPatronymic;
    CityArray: TCity;
    DateofPayArray: TDateOfPay;
    Number: TNumber;
    CurrentOffset, Offset: integer;
    OneByte: ansichar;
    NumberOfDays: longWord;
begin
    assign(SourceFile, getCurrentDir + '\' + FILE_NAME);
    reset(SourceFile);
    Offset := START_SUBSCRIBER_OFFSET;
    Seek(SourceFile, Offset);
    while not EOF(SourceFile) do
    begin
        blockRead(SourceFile, OneByte, 1);
        if OneByte <> DELETER then
        begin
            Seek(SourceFile, Offset);
            blockRead(SourceFile, Number, NUMBER_LENGTH);
            if isRequiredSubscriber(SourceFile, TelephoneNumberArray,
              SurnameArray, NameArray, PatromynicArray, CityArray,
              RequiredSubscriber) then
            begin
                blockRead(SourceFile, DateOfPayArray, DATE_OF_PAY_LENGTH);
                NumberOfDays := dateToNumber(DateOfPayArray);
                SubscriberList.add(TelephoneNumberArray, SurnameArray,
                  NameArray, PatromynicArray, CityArray, NumberOfDays, Number);
            end;
        end;
        Offset := Offset + RECORD_SIZE;
        Seek(SourceFile, Offset);
    end;
    close(SourceFile);
end;