import java.util.*; import java.io.*; import java.math.*;
public class Main{
	//Don't have to see. start------------------------------------------
	static class InputIterator{
		ArrayList<String> inputLine = new ArrayList<String>(1024);
		int index = 0; int max; String read;
		InputIterator(){
			BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
			try{
				while((read = br.readLine()) != null){
					inputLine.add(read);
				}
			}catch(IOException e){}
			max = inputLine.size();
		}
		boolean hasNext(){return (index < max);}
		String next(){
			if(hasNext()){
				return inputLine.get(index++);
			}else{
				throw new IndexOutOfBoundsException("There is no more input");
			}
		}
	}
	static HashMap<Integer, String> CONVSTR = new HashMap<Integer, String>();
	static InputIterator ii = new InputIterator();//This class cannot be used in reactive problem.
	static PrintWriter out = new PrintWriter(System.out);
	static void flush(){out.flush();}
	static void myout(Object t){out.println(t);}
	static void myerr(Object t){System.err.print("debug:");System.err.println(t);}
	static String next(){return ii.next();}
	static boolean hasNext(){return ii.hasNext();}
	static int nextInt(){return Integer.parseInt(next());}
	static long nextLong(){return Long.parseLong(next());}
	static double nextDouble(){return Double.parseDouble(next());}
	static ArrayList<String> nextStrArray(){return myconv(next(), 8);}
	static ArrayList<String> nextCharArray(){return myconv(next(), 0);}
	static ArrayList<Integer> nextIntArray(){
		ArrayList<String> input = nextStrArray(); ArrayList<Integer> ret = new ArrayList<Integer>(input.size());
		for(int i = 0; i < input.size(); i++){
			ret.add(Integer.parseInt(input.get(i)));
		}
		return ret;
	}
	static ArrayList<Long> nextLongArray(){
		ArrayList<String> input = nextStrArray(); ArrayList<Long> ret = new ArrayList<Long>(input.size());
		for(int i = 0; i < input.size(); i++){
			ret.add(Long.parseLong(input.get(i)));
		}
		return ret;
	}
	static String myconv(Object list, int no){//only join
		String joinString = CONVSTR.get(no);
		if(list instanceof String[]){
			return String.join(joinString, (String[])list);
		}else if(list instanceof ArrayList){
			return String.join(joinString, (ArrayList)list);
		}else{
			throw new ClassCastException("Don't join");
		}
	}
	static ArrayList<String> myconv(String str, int no){//only split
		String splitString = CONVSTR.get(no);
		return new ArrayList<String>(Arrays.asList(str.split(splitString)));
	}
	public static void main(String[] args){
		CONVSTR.put(8, " "); CONVSTR.put(9, "\n"); CONVSTR.put(0, "");
		solve();flush();
	}
	//Don't have to see. end------------------------------------------
	static int output = 5000;
	static int N;
	static int K;
	static Node[] list;
	static int maxDepth = -1;
	static void solve(){//Here is the main function
		ArrayList<Integer> one = nextIntArray();
		N = one.get(0);
		K = one.get(1);
		list = new Node[N];
		for(int i = 0; i < N; i++){
			list[i] = new Node();
		}
		Edge[] e = new Edge[N - 1];
		for(int i = 0; i < N - 1; i++){
			ArrayList<Integer> tmp = nextIntArray();
			e[i] = new Edge(tmp);
			list[tmp.get(0) - 1].child.add(tmp.get(1) - 1);
			list[tmp.get(1) - 1].child.add(tmp.get(0) - 1);
		}
		for(int i = 0; i < N; i++){
			if(list[i].child.size() == 1){
				fbfs(i);
			}
		}
		if(K % 2 == 1){
			for(int i = 0; i < N - 1; i++){
				bfs(e[i].p.get(0) - 1, e[i].p.get(1) - 1);
			}
		}else{
			for(int i = 0; i < N; i++){
				bfs(i);
			}
		}
		myout(output);
	}
	//Method addition frame start

static class Node{
	boolean access = false;
	ArrayList<Integer> child = new ArrayList<Integer>();
	int depth = 0;
	Node(){}
}

static class Edge{
	ArrayList<Integer> p;
	Edge(ArrayList<Integer> p){
		this.p = p;
	}
}

static void fbfs(int s){
	reset();
	ArrayDeque<Integer> queue = new ArrayDeque<Integer>();
	queue.add(s);
	list[s].access = true;
	while(queue.size() > 0){
		int now = queue.pollFirst();
		ArrayList<Integer> child = list[now].child;
		for(int i = 0; i < child.size(); i++){
			if(!list[child.get(i)].access){
				list[child.get(i)].access = true;
				list[child.get(i)].depth = list[now].depth + 1;
				maxDepth = Math.max(maxDepth, list[child.get(i)].depth);
				queue.addLast(child.get(i));
			}
		}
	}
}
static void bfs(int s){
	bfs(s, -1);
}
static void bfs(int s, int s2){
	reset();
	int count = 0;
	ArrayDeque<Integer> queue = new ArrayDeque<Integer>();
	queue.add(s);
	list[s].access = true;
	if(s2 != -1){
		list[s2].access = true;
		queue.addLast(s2);
	}
	while(queue.size() > 0){
		int now = queue.pollFirst();
		if(list[now].depth > K / 2){
			count++;
		}
		ArrayList<Integer> child = list[now].child;
		for(int i = 0; i < child.size(); i++){
			if(!list[child.get(i)].access){
				list[child.get(i)].access = true;
				list[child.get(i)].depth = list[now].depth + 1;
				queue.addLast(child.get(i));
			}
		}
	}
	output = Math.min(output, count);
}
static void reset(){
	for(int i = 0; i < N; i++){
		list[i].access = false;
		list[i].depth = 0;
	}
}



	//Method addition frame end
}


Measured memory_bytes: 53872