# Value: 4 points
case 1
case 2
book a 10 10
book b 20 20
book c 30 30
shelf 1 30 30
shelf 1 30 30
shelf 1 30 30
add a 1
add b 1
add c 1
shelf 2 20 20
shelf 2 30 30
shelf 2 40 40
add a 2
add b 2
add c 2
pcase 1
pcase 2