The input consist of a number of cases. Each case starts with two non-negative integer n and m, satisfying n <= 500 and m <= n(n-1)/2. This is followed by m lines,each containing two integers specifying the two vertices connected by an edge. The vertices are labeled from 1 to n. The end of input is indicated by a line containing n = m = 0.

　　For each case,print one of the following lines depending on how
　　many different connected components are trees.(T > 1 below):
　　 Case x: A forest of T trees.
　　 Case x: There is one tree.
　　 Case x: No Trees.
　　x is the case number (starting from 1).
　　

6 3
1 2
2 3
3 4
6 5
1 2
2 3
3 4
4 5
5 6
6 6
1 2
2 3
1 3
4 5
5 6
6 4
0 0

Case 1: A forest of 3 trees.
Case 2: There is one tree.
Case 3: No Trees.