#include <iostream>
#include <stdio.h>
#include <fstream>
#include <queue>
#include <iomanip>
#include <cstdio>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <time.h>
#include <cassert>
#include <map>
#include <set>
#include <stack>
#include <time.h>
#include <cstdlib>
#include <cstring>
#include <string.h>
#include <bitset>
#include <ctype.h>

#include <complex>

//#include <unordered_map>
//#include <unordered_set>

#define llong long long int
#define pb push_back
#define mp make_pair
#define pr pair <int, int>
#define X first
#define Y second
#define endl "\n"
using namespace std;
const int MAXN = 1e6 + 50;
const int INF = 1e9 + 7;
//const llong LINF = 1e18;
const int MOD = 1e9 + 7;

int n, d;
vector<int> a[MAXN];
int depth[MAXN];
int component[MAXN];
int get(int x) {
    if (component[x] == x) {
        return x;
    }
    return component[x] = get(component[x]);
}
inline void do_uninon(int x, int y) {
    x = get(x);
    y = get(y);
    if (x != y)
        component[x] = y;
}
int getdiameter(int x, int p = -1) {
    if (p != -1) {
        depth[x] = depth[p] + 1;
    } else {
        depth[x] = 0;
    }
    int cur = x;
    for (auto i: a[x]) {
        if (i != p) {
            int tmp = getdiameter(i, x);
            if (depth[tmp] > depth[cur]) {
                cur = tmp;
            }
        }
    }
    return cur;
}
int level[MAXN], whoonthislevel[MAXN];
int mx[MAXN];
vector<int> v[MAXN];

void dfs(int x, int p = -1) {
    v[x].clear();
    if (p == -1) {
        level[x] = 0;
    } else {
        level[x] = level[p] + 1;
    }
    whoonthislevel[level[x]] = x;
    if (level[x] >= d) {
        do_uninon(x, whoonthislevel[level[x] - d]);
    }
    mx[x] = level[x];

    for (auto i: a[x]) {
        if (i == p) {
            continue;
        }
        dfs(i, x);
        if (v[x].size() < v[i].size()) {
            swap(v[x], v[i]);
            swap(mx[x], mx[i]);
        }
        for (auto j: v[i]) {
            int c = level[j] - level[x];
            if (c < d && level[x] >= c && mx[x] - level[x] >= d - c) {
                do_uninon(j, whoonthislevel[level[x] - c]);
            }
            v[x].pb(j);
        }
        mx[x] = max(mx[x], mx[i]);
    }
    v[x].pb(x);

}
int main() {
#ifdef DEBUG
    double beg = clock();
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
    //freopen("sump.in", "r", stdin);
    //freopen("sump.out", "w", stdout);
#endif
    //ios_base::sync_with_stdio(0);cin.tie();
    scanf("%d%d", &n, &d);
    for (int i = 1; i < n; i++) {
        int x, y;
        scanf("%d%d", &x, &y);
        a[x].pb(y);
        a[y].pb(x);
    }
    for (int i = 1; i <= n; i++) {
        component[i] = i;
    }
    int D1 = getdiameter(1);
    int D2 = getdiameter(D1);
    dfs(1);
    dfs(D1);
    dfs(D2);
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        int x = get(i);

        if (x == i) {
            ans++;
        }
    }
    cout << ans;
#ifdef DEBUG
    double end = clock();
    fprintf(stderr, "\n*** Total time = %.3lf ***\n", (end - beg) / CLOCKS_PER_SEC);
#endif
    return 0;
}