B"In Homer's country, there are n cities numbered 1 to n and they form a tree. That is, there are (n-1) undirected roads between these n cities and every two cities can reach each other through these roads. Homer's country is an industrial country, and each of the n cities in it contains some mineral resource. The mineral resource of city i is labeled a_i . Homer is given the plans of the country in the following q years. The plan of the i -th year is described by four parameters u_i, v_i, l_i and r_i , and he is asked to find any mineral resource c_i such that the following two conditions hold: As the best friend of Homer, he asks you for help. For every plan, find any such mineral resource c_i , or tell him that there doesn't exist one. The first line contains two integers n ( 1 <= q n <= q 3 cdot 10^5 ) and q ( 1 <= q q <= q 3 cdot 10^5 ), indicating the number of cities and the number of plans. The second line contains n integers a_1, a_2, ... , a_n ( 1 <= q a_i <= q n ). Then the i -th line of the following (n-1) lines contains two integers x_i and y_i ( 1 <= q x_i, y_i <= q n ) with x_i neq y_i , indicating that there is a bidirectional road between city x_i and city y_i . It is guaranteed that the given roads form a tree. Then the i -th line of the following q lines contains four integers u_i , v_i , l_i , r_i ( 1 <= q u_i <= q n , 1 <= q v_i <= q n , 1 <= q l_i <= q r_i <= q n ), indicating the plan of the i -th year. Print q lines, the i -th of which contains an integer c_i such that In the first three queries, there are four cities between city 3 and city 5 , which are city 1 , city 2 , city 3 and city 5 . The mineral resources appear in them are mineral resources 1 (appears in ci"...