B'This is an interactive problem. Given a simple undirected graph with n vertices numbered from 1 to n , your task is to color all the vertices such that for every color c , the following conditions hold: Initially, you are only given the number n of vertices and the degree of each vertex. In each query, you can choose a vertex u . As a response, you will be given the k -th edge incident to u , if this is the k -th query on vertex u . You are allowed to make at most n queries. An undirected graph is simple if it does not contain multiple edges or self-loops. The degree of a vertex is the number of edges incident to it. A set S of vertices is connected if for every two different vertices u, v in S , there is a path, which only passes through vertices in S , that connects u and v . That is, there is a sequence of edges (u_1, v_1), (u_2, v_2), ... , (u_k, v_k) with k geq 1 such that Each test contains multiple test cases. The first line contains an integer t ( 1 <= q t <= q 1000 ) -- the number of test cases. The following lines contain the description and the interactive section of each test case. For each test case, you begin the interaction by reading an integer n ( 1 <= n <= 1000 ) in the first line, indicating the number of vertices in the graph. The second line contains n integers d_1, d_2, ... , d_n ( 0 <= q d_i <= q n - 1 ), where d_i is the degree of vertex i . To make a query on vertex u ( 1 <= q u <= q n ), you should output To give the answer, you should output It is guaranteed that the graph is a simple undirected graph. It is guaranteed that the sum of n over all test cases does not exceed 1000 . In case your query format is invalid, or you have made more than n "?" queries, you will receive Wrong Answer verdict. After printing a query, do not forget to output end'...