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#include<cstdio>
#include<algorithm>
using namespace std;
#define re register
const int MAXn = 1e6;
const int MAXm = MAXn;
const int INF = 0x3f3f3f3f;

template<class T>
inline void read(T &a) {
    re char c;for (c = getchar(); (c < '0' || c > '9') && c != '-'; c = getchar());re bool f = c == '-';re T x = f ? 0 : c - '0';for (c = getchar(); c >= '0' && c <= '9'; c = getchar()) {x = (x << 1) + (x << 3) + c - '0';}a = f ? -x : x;
}

int head[MAXn + 10], cntnex, nex[MAXm * 2 + 10], to[MAXm * 2 + 10];
void Insert(int u, int v) {
    nex[++cntnex] = head[u];
    head[u] = cntnex;
    to[cntnex] = v;
}

int n, k, ans, root = 1;
bool vis[MAXn + 10];
pair<int, bool> Dfs(int cur) { // 0: hav, 1: ned
    vis[cur] = 1;
    int ned = -INF, hav = -INF;
    for (re int i = head[cur]; i; i = nex[i]) {
        if (vis[to[i]]) continue;
        pair<int, bool> tmp = Dfs(to[i]);
        if (tmp.second) {
            ned = max(ned, tmp.first);
        } else {
            hav = max(hav, tmp.first);
        }
    }
    if (cur == root) {
        if (ned == -INF && hav == -INF) {
            ++ans;
        } else if (ned == -INF) {
            ;
        } else if (hav == -INF) {
            ++ans;
        } else {
            if (ned > hav) {
                ++ans;
            } else {
                ;
            }
        }
        return make_pair(-1, -1);
    }
    if (ned == -INF && hav == -INF) {
        return make_pair(1, 1);
    } else if (ned == -INF) {
        if (hav == 0) {
            return make_pair(0, 1);
        } else {
            return make_pair(hav - 1, 0);
        }
    } else if (hav == -INF) {
        if (ned == k) {
            ++ans;
            return make_pair(k - 1, 0);
        } else {
            return make_pair(ned + 1, 1);
        }
    } else {
        if (ned > hav) {
            if (ned == k) {
                ++ans;
                return make_pair(k - 1, 0);
            } else {
                return make_pair(ned + 1, 1);
            }
        } else {
            if (hav == 0) {
                return make_pair(0, 1);
            } else {
                return make_pair(hav - 1, 0);
            }
        }
    }
}

int main() {
    read(n);
    read(k);
    if (k == 0) {
        printf("%d\n", n);
        return 0;
    }
    for (re int i = 1, u, v; i < n; ++i) {
        read(u), read(v);
        Insert(u, v); Insert(v, u);
    }
    Dfs(root);
    printf("%d\n", ans);
}