Black and White

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Medium
Problem

You are given a tree with N nodes, with the nodes numbered from 1  to N . Each node is colored either black or white, which is given to you. Find the length of the longest simple path with alternating colors(any two adjacent nodes *in the path* should have different colors).

Input format

First line has N.

Next N1 lines each of the form u v indicating there is an edge between node u and node v.

Next N space separated booleans, ith of them represents ith node color in the tree.

Output format

Print length of the longest path.

Constraints

1 <= N <= 10^5

Time Limit: 1.5
Memory Limit: 256
Source Limit:
Explanation

1 2 3 is the longest path with required properties. There is an edge between 1 2 and 2 3. Their colors are alternating.

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