A maximum delay of a combinational circuit is accurately reduced in consideration of a correlation between variations in delays of devices and interconnects. The connector modules are individual modules in the sense that they are separated from one another. The urine bag can be worn to collect urine from a user who does not have convenient access to a toilet, and the urine bag is disposable after use. Cleaning larger pans is simplified by placing the sifter at one end and lifting the opposite end of the box, while sliding the sifter toward the raised end permitting gravity to sift the litter through the screen.