Kol5

Program Kalendarz;


function jakiDzien(d, m, r : integer) : integer;
var n : integer;
begin
  n := 6 + d + r - 1900 + (r - 1900) div 4;

  case m of
    4, 7: ;
    1, 10: n := n + 1;
    5: n := n + 2;
    8: n := n + 3;
    2, 3, 11: n := n + 4;
    6: n := n + 5;
    9, 12: n := n + 6;
  end;

  if((r mod 4) = 0) and (m < 3) then n := n - 1;
  jakiDzien := n mod 7;
end;

function ilePiatkow13() : integer;
var i, j : integer;
begin
  ilePiatkow13 := 0;
  for i := 2007 to 2011 do
  begin
    for j := 1 to 12 do
    begin
      if jakiDzien(13, j, i) = 5 then Inc(ilePiatkow13);
    end;
  end;
end;

var
  i : integer;

begin
  Writeln(ilePiatkow13());
  Readln(i);
end.