zakaz_28_02_2021_v2

program zakaz_28_02_2021_v2;

{$APPTYPE CONSOLE}
{$R *.res}

uses
    System.SysUtils;

type
    TYear = 1900 .. 1999;
    TMonth = (Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec);
    TDayOfWeek = (MON, TUE, WED, THU, FRI, SAT, SUN);

const
    ArrOfMonth: array [0 .. 11] of string = ('Янв', 'Фев', 'Мар', 'Апр', 'Май',
      'Июнь', 'Июль', 'Авг', 'Сен', 'Окт', 'Ноя', 'Дек');

var
    Year: TYear;
    Month: TMonth;
    DayOfWeek: TDayOfWeek;
    QuantityOfDays, QuantityOfDates, i: Byte;

begin
    DayOfWeek := SAT;
    QuantityOfDays := 28;

    QuantityOfDates := 0;

    for Year := 1900 to 1999 do
    begin
        for Month := Jan to Dec do
        begin
            for i := 1 to QuantityOfDays - 28 do
            begin
                if DayOfWeek = SUN then
                    DayOfWeek := MON
                else
                    DayOfWeek := Succ(DayOfWeek);
            end;

            if DayOfWeek = FRI then
            begin
                Writeln('13 ', ArrOfMonth[Ord(Month)], ' ', Year);
                Inc(QuantityOfDates);
            end;

            if Month < Aug then
            begin
                if Month = Feb then
                begin
                    if (Year mod 4 = 0) and (Year <> 1900) then
                        QuantityOfDays := 29
                    else
                        QuantityOfDays := 28;
                end
                else
                begin
                    if Ord(Month) mod 2 = 1 then
                        QuantityOfDays := 30
                    else
                        QuantityOfDays := 31;
                end;
            end
            else if Ord(Month) mod 2 = 0 then
                QuantityOfDays := 30
            else
                QuantityOfDays := 31;
        end;
    end;
    Writeln('Пятниц 13 в с 1900 до 1999: ', QuantityOfDates);
    Readln;

end.