Hi,
I was going through MAX-HEAPIFY and I encounterd like this

The running time of MAX-HEAPIFY on a subtree of size n rooted at given node i is the Θ(1) time to fix up the relationships among the elements A[i], A[LEFT(i)], and A[RIGHT(i)], plus the time to run MAX-HEAPIFY on a subtree rooted at one of the children of node i. The children's subtrees each have size at most 2n/3


I am not able to understand why children's subtrees each can have size at most equal to 2n/3 ? where this comes from ?????