#include <bits/stdc++.h>
using namespace std;
#define int long long
constexpr int H = 3;
typedef array<int,H> Hash;
constexpr Hash MOD = {1000000007, 998244353, 998244853};
int32_t main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int N, M;
cin >> N >> M;
vector<Hash> fp(N * 2 + 5);
fp[0] = {1, 1, 1};
for (int i = 1; i < fp.size(); ++i) {
for (int j = 0; j < H; ++j) {
fp[i][j] = fp[i-1][j] * 2;
if (fp[i][j] >= MOD[j]) fp[i][j] -= MOD[j];
}
}
vector<vector<int>> tree(N);
for (int i = 0; i < N - 1; ++i) {
int u, v;
cin >> u >> v;
tree[u-1].push_back(v-1);
tree[v-1].push_back(u-1);
}
vector<Hash> hash(N);
vector<int> red(N), subsz(N, 1), par(N, -1);
auto dfs = [&](int node, int lnode, auto&&dfs)->void{
par[node] = lnode;
vector<pair<Hash, int>> c;
for (auto it : tree[node]) if (it != lnode) {
dfs(it, node, dfs);
c.push_back({hash[it], subsz[it]});
subsz[node] += subsz[it];
red[node] += red[it];
}
red[node] += subsz[node];
sort(c.begin(), c.end());
c.push_back({{1, 1, 1}, 1});
int pref = 1;
for (auto &[hsh, sz] : c) {
for (int i = 0; i < H; ++i) {
hash[node][i] += fp[pref][i];
if (hash[node][i] >= MOD[i]) hash[node][i] -= MOD[i];
}
pref += sz * 2;
}
};
dfs(0, -1, dfs);
map<Hash, int> mp;
for (int i = 0; i < N; ++i) {
mp[hash[i]]++;
}
set<Hash> ans;
for (int nd = 0; nd < N; ++nd) {
if (red[nd] + M == N) {
map<Hash, int> t;
queue<array<int,3>> q;
q.push({nd, par[nd], 1});
while (q.size()) {
int node = q.front()[0];
int lnode = q.front()[1];
int w = q.front()[2];
q.pop();
t[hash[node]] += w;
for (auto it : tree[node]) if (it != lnode) {
q.push({it, node, w + 1});
}
}
for (auto [h, k] : t) {
if (mp[h] < k) {
goto mahmut;
}
}
ans.insert(hash[nd]);
mahmut:;
}
}
cout << ans.size() << '\n';
}
