The vacuum cleaner in this home has three filters. Not one... not two... and certainly not four. The number of the filters is three, three being the number of filters. Four is too many, and two is right out.
Experience in life has taught me several things regarding vacuum cleaner filters, and what will not happen in dealing with them.
One (1): If I do not clean the vacuum cleaner filters, they will never be cleaned.
Two (2): If the vacuum cleaner filters are not serviced, the vacuum will not suck.