#include <bits/stdc++.h>
using namespace std;
const int N = 1e6 + 5, inf = 1e9 + 7;
vector<int> vec[N];
int n, k, mx, nod, now, cnt[N], siz[N];
bool vs[N];
long long int rs;
void dfs(int u, int pr) {
  nod++, siz[u] = 1;
  for (auto v : vec[u]) {
    if (v == pr || vs[v]) continue;
    dfs(v, u);
    siz[u] += siz[v];
  }
}
int centroid(int u, int pr) {
  for (auto v : vec[u]) {
    if (v == pr || siz[v] <= nod / 2 || vs[v]) continue;
    return centroid(v, u);
  }
  return u;
}
void add(int u, int pr, int dis) {
  cnt[dis]++;
  mx = max(mx, dis);
  for (auto v : vec[u]) {
    if (v == pr || vs[v]) continue;
    add(v, u, dis + 1);
  }
}
void cal(int u, int pr, int dis) {
  if (k >= dis) {
    now += cnt[k - dis];
  } else
    return;
  for (auto v : vec[u]) {
    if (v == pr || vs[v]) continue;
    cal(v, u, dis + 1);
  }
}
void decomposed(int u, int pr) {
  nod = 0;
  dfs(u, pr);
  int rt = centroid(u, pr);
  vs[rt] = true;
  mx = 0, now = 0;
  for (auto v : vec[rt]) {
    if (v == pr || vs[v]) continue;
    cal(v, rt, 1);
    add(v, rt, 1);
  }
  rs += now;
  for (int i = 1; i <= mx; i++) {
    cnt[i] = 0;
  }
  for (auto v : vec[rt]) {
    if (v == pr || vs[v]) continue;
    decomposed(v, rt);
  }
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> k;
  int m = n - 1;
  cnt[0] = 1;
  while (m--) {
    int u, v;
    cin >> u >> v;
    vec[u].push_back(v);
    vec[v].push_back(u);
  }
  decomposed(1, -1);
  cout << rs << "\n";
  return 0;
}
