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