Lech Lecha: The Bris Between the Animal Parts

At the bris between the parts Hashem told Avraham  to bring three heifers, three goats, three rams, a turtledove, and a young dove as a sacrifice. He cut the animals in half, but he did not cut the birds in half [Bereishis  15: 9-10].

Question: How many total animal parts did he have?

Answer: 9 animals cut in ½ = 18

2 birds = 2

Total 20 parts