24. A pond filled with water, first put the fish into the pond, 2 liters of water overflow; then take out the fish, put the crab into the pond, another 3 liters of water overflow; take out the crab again, put the turtle into the pond, another 5 liters of water overflow. If the fish, crab, and turtle are put into the pond filled with water at the same time, the amount of water that overflows is $\qquad$ liters. (Neglecting any water loss during the process of putting in and taking out)
17