It’s two negative commandments (chametz should not be seen/ should not be found), plus one positive commandment (to eliminate chametz).
The point is that every moment that the chametz exists, he transgresses three sins from the Torah. Again, and again, and again. Therefore, to buy chametz at the zoo on Pesach is much worse than eating a slice of pork. And to speak lashon hara for one minute is much worse than eating a slice of pork. And much worse than drinking cholov stam, or not wearing a white shirt.