#include <cassert>// c
#include <iostream>// io
#include <iomanip>
#include <fstream>
#include <sstream>
#include <vector>// container
#include <map>
#include <set>
#include <queue>
#include <bitset>
#include <stack>
#include <algorithm>// other
#include <complex>
#include <numeric>
#include <functional>
#include <random>
#include <regex>
using namespace std;

typedef long long ll;typedef unsigned long long ull;typedef long double ld;

#define ALL(c) c.begin(),c.end()
#define IN(l,v,r) (l<=v && v < r)
template<class T> void UNIQUE(T& v){v.erase(unique(ALL(v)),v.end());}
//debug
#define DUMP(x) cerr << #x <<" = " << (x)
#define LINE() cerr<< " (L" << __LINE__ << ")"

struct range{
	struct Iter{
		int v,step;
		Iter& operator++(){v+=step;return *this;}
		bool operator!=(Iter& itr){return v<itr.v;}
		int& operator*(){return v;}
	};
	Iter i, n;
	range(int i, int n,int step):i({i,step}), n({n,step}){}
	range(int i, int n):range(i,n,1){}
	range(int n):range(0,n){}
	Iter& begin(){return i;}
	Iter& end(){return n;}
};
struct rrange{
	struct Iter{
		int v,step;
		Iter& operator++(){v-=step;return *this;}
		bool operator!=(Iter& itr){return v>itr.v;}
		int& operator*(){return v;}
	};
	Iter i, n;
	rrange(int i, int n,int step):i({i-1,step}), n({n-1,step}){}
	rrange(int i, int n):rrange(i,n,1){}
	rrange(int n) :rrange(0,n){}
	Iter& begin(){return n;}
	Iter& end(){return i;}
};

//input
template<typename T1,typename T2> istream& operator >> (istream& is,pair<T1,T2>& p){return is>>p.first>>p.second;}
template<typename T1> istream& operator >> (istream& is,tuple<T1>& t){return is >> get<0>(t);}
template<typename T1,typename T2> istream& operator >> (istream& is,tuple<T1,T2>& t){return is >> get<0>(t) >> get<1>(t);}
template<typename T1,typename T2,typename T3> istream& operator >> (istream& is,tuple<T1,T2,T3>& t){return is >>get<0>(t)>>get<1>(t)>>get<2>(t);}
template<typename T1,typename T2,typename T3,typename T4> istream& operator >> (istream& is,tuple<T1,T2,T3,T4>& t){return is >> get<0>(t)>>get<1>(t)>>get<2>(t)>>get<3>(t);}
template<typename T> istream& operator >> (istream& is,vector<T>& as){for(int i:range(as.size()))is >>as[i];return is;}
//output
template<typename T> ostream& operator << (ostream& os, const set<T>& ss){for(auto a:ss){if(a!=ss.begin())os<<" "; os<<a;}return os;}
template<typename T1,typename T2> ostream& operator << (ostream& os, const pair<T1,T2>& p){return os<<p.first<<" "<<p.second;}
template<typename K,typename V> ostream& operator << (ostream& os, const map<K,V>& m){bool isF=true;for(auto& p:m){if(!isF)os<<endl;os<<p;isF=false;}return os;}
template<typename T1> ostream& operator << (ostream& os, const tuple<T1>& t){return os << get<0>(t);}
template<typename T1,typename T2> ostream& operator << (ostream& os, const tuple<T1,T2>& t){return os << get<0>(t)<<" "<<get<1>(t);}
template<typename T1,typename T2,typename T3> ostream& operator << (ostream& os, const tuple<T1,T2,T3>& t){return os << get<0>(t)<<" "<<get<1>(t)<<" "<<get<2>(t);}
template<typename T1,typename T2,typename T3,typename T4> ostream& operator << (ostream& os, const tuple<T1,T2,T3,T4>& t){return os << get<0>(t)<<" "<<get<1>(t)<<" "<<get<2>(t)<<" "<<get<3>(t);}
template<typename T> ostream& operator << (ostream& os, const vector<T>& as){for(int i:range(as.size())){if(i!=0)os<<" "; os<<as[i];}return os;}
template<typename T> ostream& operator << (ostream& os, const vector<vector<T>>& as){for(int i:range(as.size())){if(i!=0)os<<endl; os<<as[i];}return os;}

// values
template<typename T> inline T INF(){assert(false);};
template<> inline int INF<int>(){return 1<<28;};
template<> inline ll INF<ll>(){return 1LL<<58;};
template<> inline double INF<double>(){return 1e16;};
template<> inline long double INF<long double>(){return 1e16;};

template<class T> inline T EPS(){assert(false);};
template<> inline int EPS<int>(){return 1;};
template<> inline ll EPS<ll>(){return 1LL;};
template<> inline double EPS<double>(){return 1e-8;};
template<> inline long double EPS<long double>(){return 1e-8;};

// min{2^r | n < 2^r}
template<typename T> T upper_pow2(T n){ T res=1;while(res<n)res<<=1;return res;}
// max{d | 2^d  <= n}
template<typename T> T msb(T n){ int d=62;while((1LL<<d)>n)d--;return d;}

template<typename T,typename U> T pmod(T v,U M){return (v%M+M)%M;}


template<class Cost> struct Edge{
    int to;Cost cost;
    Edge(int to,Cost cost):to(to),cost(cost){};
    bool operator<(Edge r) const{ return cost<r.cost;}
    bool operator>(Edge r) const{ return cost>r.cost;}
};
template<class Cost> ostream& operator << (ostream& os, const Edge<Cost>& e){ return os<<"(->"<<e.to <<","<<e.cost<<")";}
template<class Cost> using Graph = vector<vector<Edge<Cost>>>;


vector<bool> deleted;

template<class Cost> pair<Cost,int> far(const Graph<Cost>&g,int r){
	function<pair<Cost,int>(int,int)> dfs = [&](int v,int p)->pair<Cost,int>{
		pair<Cost,int> r(0,v);
		for(auto& e:g[v])if(e.to!=p && !deleted[e.to]){
			auto t=dfs(e.to,v);
			t.first+=e.cost;
			if(r<t)r=t;
		}
		return r;
	};
	return dfs(r,-1);
}

template<class Cost> pair<Cost,int> diam(const Graph<Cost>&g){
	int i = 0; while(deleted[i])i++;
	auto f=far(g,i),t=far(g,f.second);

	int v1c = -1;
	int v1 = f.second;
	{
		int v1p;
		for(auto& e:g[v1])if(!deleted[e.to]) v1p = e.to;
		for(auto& e:g[v1p])if(!deleted[e.to]) v1c++;
	}
	int v2c = -1;
	int v2 = t.second;
	{
		int v2p;
		for(auto& e:g[v2])if(!deleted[e.to]) v2p = e.to;
		for(auto& e:g[v2p])if(!deleted[e.to]) v2c++;
	}
	if(v1c < v2c){
		return make_pair(t.first,v1);
	}else{
		return make_pair(t.first,v2);
	}
}

class Main{
	public:

	Graph<int> g;

	int dfs(int p,int v,int d){
		int c = 1;
		if(d == 0) return c;
		for(auto& e: g[v])if(e.to != p){
			c += dfs(v,e.to,d-1);
		}
		return c;
	}

	void run(){
		int N,K;cin >> N >> K;
		g = vector<vector<Edge<int>>>(N);
		for(int i:range(N-1)){
			int a,b;cin >> a >> b;a--;b--;
			g[a].push_back({b,1});
			g[b].push_back({a,1});
		}

		int mv = INF<int>();
		for(int i:range(N))for(auto& e:g[i]){
			mv = min(mv,N-(dfs(i,e.to,(K-1)/2)+dfs(e.to,i,(K-1)-(K-1)/2)));
			mv = min(mv,N-(dfs(i,e.to,(K-1)-(K-1)/2)+dfs(e.to,i,(K-1)/2)));
		}
		cout << mv << endl;
	}
};

int main(){
	cout <<fixed<<setprecision(20);
	cin.tie(0);
	ios::sync_with_stdio(false);
	Main().run();
	return 0;
}


Measured memory_bytes: 384