var X,Y: integer;

begin 
  case GetZ of
    3..5: X := GetX; 
    6: X := GetX + 4;
    7: X := GetX + 7;
    8: X := GetX + 15;
    9: X := GetX + 66;
    10: X := GetX + 132;
    11: X := GetX + 447;
    12: X := GetX + 893;
    13: X := GetX + 1785;
    14: X := GetX + 3570;
  end;

  case GetZ of
    3..5: Y := GetY; 
    6: Y := GetY - 4;
    7: Y := GetY - 8;
    8: Y := GetY - 15;
    9: Y := GetY - 69;
    10: Y := GetY - 138;
    11: Y := GetY - 468;
    12: Y := GetY - 936;
    13: Y := GetY - 1871;
    14: Y := GetY - 3742;
  end;

  ResultURL:=GetURLBase+inttostr(GetZ - 3)+'/'+inttostr(X)+'/'+inttostr(round(intpower(2,GetZ-1)-(Y+1)))+'.jpeg';
end.


