B'Hossam has an unweighted tree G with letters in vertices. Hossam defines s(v, , u) as a string that is obtained by writing down all the letters on the unique simple path from the vertex v to the vertex u in the tree G . A string a is a subsequence of a string s if a can be obtained from s by deletion of several (possibly, zero) letters. For example, "dores", "cf", and "for" are subsequences of "codeforces", while "decor" and "fork" are not. A palindrome is a string that reads the same from left to right and from right to left. For example, "abacaba" is a palindrome, but "abac" is not. Hossam defines a sub-palindrome of a string s as a subsequence of s , that is a palindrome. For example, "k", "abba" and "abhba" are sub-palindromes of the string "abhbka", but "abka" and "cat" are not. Hossam defines a maximal sub-palindrome of a string s as a sub-palindrome of s , which has the maximal length among all sub-palindromes of s . For example, "abhbka" has only one maximal sub-palindrome -- "abhba". But it may also be that the string has several maximum sub-palindromes: the string "abcd" has 4 maximum sub-palindromes. Help Hossam find the length of the longest maximal sub-palindrome among all s(v, , u) in the tree G . Note that the sub-palindrome is a subsequence, not a substring. The first line contains one integer t ( 1 <= t <= 200 ) -- the number of test cases. The first line of each test case has one integer number n ( 1 <= n <= 2 cdot 10^3 ) -- the number of vertices in the graph. The second line contains a string s of length n , the i -th symbol of which denotes the letter on the vertex i . It is guaranteed that all characters in this string are lowercase English letters. The next n - 1 lines describe the edges of the tree. Each edge is given by two integers v and u ( 1 <= v, , u <= n , '...