I’m going to agree with you but would change it to A6-A19. With A20, mailboxes are, for me, a huge source of money on Day 1 as they always contain books. The first thing that I do when I reach a town is to hit all of the mailboxes and some of the newspaper stands if I’m brave then sell all of them. At that point I have around $2000 or more to buy food and ammo or whatever I need. When they respawn on Day 10, I return and loot to read.