Young gardener

Mom asked Vasya to water all the young trees in the garden. Vasya knows that while trees are small, they need to be well watered. However, he does not know exactly how much water they need. Vasya is a clever boy: he carefully read a botany textbook and learned that the amount of water needed is directly proportional to the total number of leaves on the tree. For good growth, it is enough to pour one liter of water for each leaf.

Fortunately, Vasya found that the leaves on the trees grow in layers: the top layer has two leaves, the second layer has four leaves, the next has six, and so on, with each subsequent layer having two more leaves than the previous one. Additionally, there is one extra leaf growing at the very tip of the tree. Sly Vasya sent his younger sister Masha to count the number of layers on each tree, and asks you to write a program that calculates how much water each tree needs.