#include <bits/stdc++.h>
#define int long long
#define ll long long
using ull = unsigned long long;
using namespace std;
#define dump(x)                             \
    if (dbg) {                              \
        cerr << #x << " = " << (x) << endl; \
    }
#define overload4(_1, _2, _3, _4, name, ...) name
#define FOR1(n) for (ll i = 0; i < (n); ++i)
#define FOR2(i, n) for (ll i = 0; i < (n); ++i)
#define FOR3(i, a, b) for (ll i = (a); i < (b); ++i)
#define FOR4(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define FOR(...) overload4(__VA_ARGS__, FOR4, FOR3, FOR2, FOR1)(__VA_ARGS__)
#define FORR(i, a, b) for (int i = (a); i <= (b); ++i)
#define bit(n, k) ((n >> k) & 1) /*nのk bit目*/
namespace mydef {
const int INF = 1ll << 60;
const int MOD = 1e9 + 7;
template <class T>
bool chmin(T& a, const T& b) {
    if (a > b) {
        a = b;
        return 1;
    } else
        return 0;
}
template <class T>
bool chmax(T& a, const T& b) {
    if (a < b) {
        a = b;
        return 1;
    } else
        return 0;
}
void Yes(bool flag = true) {
    if (flag)
        cout << "Yes" << endl;
    else
        cout << "No" << endl;
}
void No(bool flag = true) {
    Yes(!flag);
}
void YES(bool flag = true) {
    if (flag)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
}
void NO(bool flag = true) {
    YES(!flag);
}
template <typename A, size_t N, typename T>
void Fill(A (&array)[N], const T& val) {
    std::fill((T*)array, (T*)(array + N), val);
}
bool dbg = false;
}  // namespace mydef
using namespace mydef;
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define all(v) (v).begin(), (v).end()
#define SZ(x) ((int)(x).size())
#define vi vector<int>
#define vvi vector<vector<int>>
#define vp vector<pair<int, int>>
#define vvp vector<vector<pair<int, int>>>
#define pi pair<int, int>
//#define P pair<int, int>
//#define V vector<int>
//#define S set<int>
#define asn ans

vector<vector<int>> G;
int N, K;

int MAX = 0;

int f(int idx, int par, int k) {
    if (k <= 0)
        return 0;
    int cnt = 1;
    if (k > 1) {
        for (auto& nxt : G[idx]) {
            if (nxt == par)
                continue;
            cnt += f(nxt, idx, k - 1);
        }
    } else {
        chmax(MAX, (int)(G[idx].size() - 1));
    }
    return cnt;
}

void solve() {
    int ans = INF;
    K++;
    if (K % 2)
        for (int i = 0; i < N; i++) {
            MAX = 0;
            int tmp = 0;

            tmp += f(i, -1, (K + 1) / 2);
            chmin(ans, N - tmp);
        }
    else {
        for (int i = 0; i < N; i++) {
            for (auto& j : G[i]) {
                int tmp = 0;
                tmp += f(i, j, K / 2);
                tmp += f(j, i, K / 2);
                chmin(ans, N - tmp);
            }
        }
    }
    cout << ans << endl;
}

signed main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    cin >> N >> K;
    G.resize(N);
    for (int i = 0; i < N - 1; i++) {
        int a, b;
        cin >> a >> b;
        a--;
        b--;
        G[a].emplace_back(b);
        G[b].emplace_back(a);
    }


    solve();
    return 0;
}


Measured memory_bytes: 3764