Let Kn denote the complete undirected graph with n vertices where n is an even number. In other words, Kn is a graph with n vertices where every two vertices are connected. Your task is to find the maximum number of spanning trees of Kn that can be formed in such a way that no two of these spanning trees have a common edge. Input Each test case will have an even integer n (2 ≤ n ≤ 400), the number of vertices. The last test case will be followed by a single ‘0’ denoting end of input. Output For each test case, print a line in the format, ‘Case X: Y ’, where X is the case number & Y is the maximum possible number of spanning trees. Sample Input 4 0 Sample Output Case 1: 2