You are given a rooted tree having n nodes, rooted at node 1. Every node i has two values associated with itself , and . In this tree you have to count total pairs of nodes which are beautiful. A pair of nodes i , j is beautiful if i is ancestor of node j and and .
Node i is called an ancestor of some node j, if node i is the parent of node j, or it is the ancestor of parent of node j. The root of a tree has no ancestors.
Input
First line contains a number n as input. Next lines contain two integers u , v denoting that there is an edge between the nodes u and v. Next line contains n space separated integers that denote the value for each node. Similarly next line contains n space separated integers that denote the value for each node.
Output
In the output you have to print total good pairs in the tree.
Constraints
In the given tree you can see that the following pair of nodes are good : , and