$ include "seed7_05.s7i";
  include "time.s7i";

const proc: main is func
  local
    var integer: months is 0;
    var time: firstDayInMonth is time.value;
  begin
    for firstDayInMonth.year range 1900 to 2100 do
      for firstDayInMonth.month range 1 to 12 do
        if daysInMonth(firstDayInMonth) = 31 and dayOfWeek(firstDayInMonth) = 5 then
          writeln(firstDayInMonth.year <& "-" <& firstDayInMonth.month lpad0 2);
          incr(months);
        end if;
      end for;
    end for;
    writeln("Number of months:" <& months);
  end func;