You are given a tree consising of N vertices. What is the minimum number of vertices that should be removed that all the remaining parts of the initial tree will contain less than K vertices?
Input
The first line contains one integer K.
The second line contains one integer N.
The third line contains N-1 space-separated intgers ai for 2 <= i <= N which means that vertices i and ai are connected by an edge.
Output
Output one number - answer for the question.
Constraints
We can remove vertices 2, 3, 6.