Please make the answer as detailed as possible

3. Let T be a full binary tree with root r where each node v has a variable var that can be accessed with v.var. Consider the algorithm below. What does the algorithm return when called on the root r? Here v.left and v.right are the left and the right children of v, respectively Algorithm TreeAlg(v) if v is external return 0 else v.var-1+ marsv.left.var, v.right.var) l - Tree Alg(v.left) r TreeAlg(v.right) if v.left.var