#include <bits/stdc++.h>
using namespace std;
long long n, k, t, res, f[50007][507], tr[50007];
vector<long long> adj[50007];
bool d[50007];
void dfs(long long u) {
  f[u][0] = 1, d[u] = 1;
  long long ans = 0;
  for (auto v : adj[u])
    if (!d[v]) {
      tr[v] = u, dfs(v);
      for (long long i = 1; i <= k; ++i) f[u][i] += f[v][i - 1];
    }
  for (auto v : adj[u]) {
    if (v == tr[u]) continue;
    for (long long i = 1; i < k; ++i)
      ans += (f[v][i - 1]) * (f[u][k - i] - f[v][k - i - 1]);
  }
  res += (ans / 2 + f[u][k]);
}
int main() {
  ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  cin >> n >> k;
  for (long long i = 1; i < n; ++i) {
    long long u, v;
    cin >> u >> v;
    adj[u].push_back(v), adj[v].push_back(u);
  }
  dfs(1);
  cout << res;
  return 0;
}
