/* ---------- STL Libraries ---------- */

// IO library
#include <cstdio>
#include <fstream>
#include <iomanip>
#include <ios>
#include <iostream>

// algorithm library
#include <algorithm>
#include <cmath>
#include <numeric>
#include <random>

// container library
#include <array>
#include <bitset>
#include <deque>
#include <map>
#include <queue>
#include <set>
#include <string>
#include <tuple>
#include <vector>

/* ---------- Namespace ---------- */

using namespace std;

/* ---------- Type Abbreviation ---------- */

template <typename T>
using V = vector<T>;
template <typename T, typename U>
using P = pair<T, U>;
template <typename T>
using PQ = priority_queue<T>;
template <typename T>
using GPQ = priority_queue<T, vector<T>, greater<T>>;

using ll = long long;

#define fst first
#define snd second

/* ---------- conversion ---------- */

#define INT(c) static_cast<int>(c)
#define CHAR(n) static_cast<char>(n)
#define LL(n) static_cast<ll>(n)
#define DOUBLE(n) static_cast<double>(n)

/* ---------- container ---------- */

#define ALL(v) (v).begin(), (v).end()
#define SIZE(v) (LL((v).size()))

#define FIND(v, k) (v).find(k) != (v).end()
#define VFIND(v, k) find(ALL(v), k) != (v).end()

#define gsort(b, e) sort(b, e, greater<decltype(*b)>())
#define SORT(v) sort((v).begin(), (v).end())
#define GSORT(v) sort((v).begin(), (v).end(), greater<decltype((v).front())>())

/* ----------- debug ---------- */

template <class T>
ostream& operator<<(ostream& os, vector<T> v) {
    os << "[";
    for (auto vv : v)
        os << vv << ",";
    return os << "]";
}

template <class T>
ostream& operator<<(ostream& os, set<T> v) {
    os << "[";
    for (auto vv : v)
        os << vv << ",";
    return os << "]";
}

template <class L, class R>
ostream& operator<<(ostream& os, pair<L, R> p) {
    return os << "(" << p.fst << "," << p.snd << ")";
}

/* ---------- Constants ---------- */

// const ll MOD = 1e9 + 7;
// const int INF = 1 << 25;
// const ll INF = 1LL << 50;
// const double PI = acos(-1);
// const double EPS = 1e-10;
// const ll dx[4] = {0, -1, 1, 0};
// const ll dy[4] = {-1, 0, 0, 1};
// mt19937 mt(LL(time(0)));

/* ---------- Short Functions ---------- */

template <typename T>
T sq(T a) {
    return a * a;
}

template <typename T>
T gcd(T a, T b) {
    if (a > b) return gcd(b, a);
    return a == 0 ? b : gcd(b % a, a);
}

template <typename T, typename U>
T mypow(T b, U n) {
    if (n == 0) return 1;
    if (n == 1) return b /* % MOD */;
    if (n % 2 == 0) {
        return mypow(b * b /* % MOD */, n / 2);
    } else {
        return mypow(b, n - 1) * b /* % MOD */;
    }
}

ll pcnt(ll b) {
    return __builtin_popcountll(b);
}

/* v-v-v-v-v-v-v-v-v Main Part v-v-v-v-v-v-v-v-v */

vector<int> path[3000];
int N, K;

int solve(int r) {
    int d[3000];
    fill(d, d + 3000, 3000);
    d[r] = 0;

    queue<int> que;
    que.push(r);
    while (!que.empty()) {
        int v = que.front();
        que.pop();

        for (int sv : path[v]) {
            if (d[sv] < 3000) continue;
            d[sv] = d[v] + 1;
            que.push(sv);
        }
    }

    int ret = 0;
    for (int v = 0; v < N; ++v) {
        ret += (d[v] <= K / 2);
    }
    return ret;
}

int solve(int r1, int r2) {
    int d[3000];
    fill(d, d + 3000, 3000);
    d[r1] = d[r2] = 0;

    queue<int> que;
    que.push(r1);
    que.push(r2);
    while (!que.empty()) {
        int v = que.front();
        que.pop();

        for (int sv : path[v]) {
            if (d[sv] < 3000) continue;
            d[sv] = d[v] + 1;
            que.push(sv);
        }
    }

    int ret = 0;
    for (int v = 0; v < N; ++v) {
        ret += (d[v] <= K / 2);
    }
    return ret;
}

int main() {
    cin >> N >> K;

    for (int i = 0; i < N - 1; ++i) {
        int a, b;
        cin >> a >> b;
        --a;
        --b;
        path[a].push_back(b);
        path[b].push_back(a);
    }

    int ans = N;

    if (K % 2 == 0) {
        for (int v = 0; v < N; ++v) {
            ans = min(ans, N - solve(v));
        }
    } else {
        for (int v = 0; v < N; ++v) {
            for (int sv : path[v]) {
                ans = min(ans, N - solve(v, sv));
            }
        }
    }

    cout << ans << endl;
    return 0;
}


Measured memory_bytes: 384