#include <bits/stdc++.h>
#include <functional>
#include <iomanip>
using namespace std;
	
#define int long long
#define pb push_back
#define F first
#define S second
#define FOR(i,a,b) for(int (i)=(a);(i)<(b);(i)++)
#define REP(i,n) FOR(i,0,n)
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define SORT(c) sort((c).begin(),(c).end())
#define ve vector
#define vi vector<int>
#define vp vector<pair<int,int>>
#define vvi vector<vector<int>>

using ll = long long;
ll INF = LLONG_MAX / 4 - 100;
ll mod = 1e9 + 7;
int dx[] = {-1,0,1,0}, dy[] = {0,1,0,-1};
vector<ll> prime;
	
class fact {
public:
	int fmod = 1e9+7;
	vector<int> fac, inv;
	fact (int n, int Mod = 1e9+7) {
		fmod = Mod;
		fac = vector<int>(n,0);
		inv = vector<int>(n,0);
		fac[0] = 1; for (int i = 1; i < n; i++) fac[i] = fac[i-1] * i % fmod;
		for (int i = 0;i < n;i++) inv[i] = fact::POW(fac[i],fmod-2);
	}
	ll nCr(ll n, ll r) {return (fac[n] * inv[r] % fmod) * inv[n-r] % fmod;}
	ll POW(ll a, ll b) {ll c = 1; while (b > 0) {if (b & 1) {c = a * c%fmod;}a = a * a%fmod; b >>= 1;}return c;}
};
	
template <class T = ll> T in() {T x; cin >> x; return (x);}
void DEBUG(vector<int> a) {for(int i=0;i<a.size();i++)cout<<a[i]<<" ";cout<<endl;}
void EMP(int x) {cout<<"!!!"<<x<<"!!!"<<endl;}
ll GCD(ll a, ll b) {ll c; while (b != 0) {c = a % b; a = b; b = c;}return a;}
ll LCM(ll a, ll b) {return a * b / GCD(a, b);}
ll POW(ll a, ll b) {ll c = 1; while (b > 0) {if (b & 1) {c = a * c%mod;}a = a * a%mod; b >>= 1;}return c;}
void PRI(ll n) {bool a[n + 1LL]; for (int i = 0; i < n + 1LL; i++) {a[i] = 1LL;}for (int i = 2; i < n + 1LL; i++) {if (a[i]) {prime.pb(i); ll b = i; while (b <= n) {a[b] = 0; b += i;}}}}
template <typename T> T chmin(T& a, T b) {if(a>b)a=b;return a;}
template <typename T> T chmax(T& a, T b) {if(a<b)a=b;return b;}
bool isSqrt(ll a) {return pow(sqrt(a),2) == a ? 1 : 0;}
void YesNo(bool a) {if (a) cout << "Yes"; else cout << "No"; cout << endl;}
void yesno(bool a) {if (a) cout << "yes"; else cout << "no"; cout << endl;}
void YESNO(bool a) {if (a) cout << "YES"; else cout << "NO"; cout << endl;}
double dis(int x1, int x2, int y1, int y2) {
	return sqrt((double)abs(x1-x2)*(double)abs(x1-x2)+(double)abs(y1-y2)*(double)abs(y1-y2));
}

bool solve() {
	int n, k; cin >> n >> k;
	vvi edge = vvi(n);
	REP (i,n-1) {
		int a,b; cin >> a >> b;
		edge[--a].pb(--b);
		edge[b].pb(a);
	}

	int ans = INF;
	vi dep(n);
	REP (i,n) {
		vvi sub(edge[i].size());
		fill(all(dep),-1);//各頂点は一度しか訪れないので
		dep[i] = 0;
		int tmp = 0;
		int odd = INF;

		REP (j,sub.size()) {
			dep[edge[i][j]] = 1;
			queue<int> nxt; nxt.push(edge[i][j]);
			while (!nxt.empty()) {
				int p = nxt.front(); nxt.pop();
				sub[j].pb(dep[p]);
				for (auto to : edge[p]) {
					if (dep[to] == -1) {
						dep[to] = dep[p] + 1;
						nxt.push(to);
					}
				}
			}

			if (k % 2) {
				//奇数
				int rem = upper_bound(all(sub[j]),k/2) - sub[j].begin();
				tmp += sub[j].size() - rem;
				int can = upper_bound(all(sub[j]),k/2+1) - sub[j].begin();
				chmin(odd,rem-can);
			} else {
				int rem = upper_bound(all(sub[j]),k/2) - sub[j].begin();
				tmp += sub[j].size() - rem;
			}
		}
		if (k % 2) {
			chmin(ans,tmp+odd);
		} else {
			chmin(ans,tmp);
		}
	}

	cout << ans << endl;
}

signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	solve();
}


Measured memory_bytes: 512