#include <bits/stdc++.h>
using namespace std;
vector<string> vec_splitter(string s) {
  s += ',';
  vector<string> res;
  while (!s.empty()) {
    res.push_back(s.substr(0, s.find(',')));
    s = s.substr(s.find(',') + 1);
  }
  return res;
}
void debug_out(vector<string> __attribute__((unused)) args,
               __attribute__((unused)) int idx,
               __attribute__((unused)) int LINE_NUM) {
  cerr << '\n';
}
template <typename Head, typename... Tail>
void debug_out(vector<string> args, int idx, int LINE_NUM, Head H, Tail... T) {
  if (idx > 0)
    cerr << ", ";
  else
    cerr << "Line(" << LINE_NUM << ") ";
  stringstream ss;
  ss << H;
  cerr << args[idx] << " = " << ss.str();
  debug_out(args, idx + 1, LINE_NUM, T...);
}
void run() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr), cout.tie(nullptr);
}
const int N = 5e4 + 4, MOD = 1e9 + 7, mod2 = 998244353;
int dp[N][503];
int n, k;
vector<int> adj[N];
long long ans;
void dfs(int u, int p) {
  dp[u][0] = 1;
  for (auto &v : adj[u]) {
    if (v == p) continue;
    dfs(v, u);
    for (int i = 0; i < k; ++i) {
      dp[u][i + 1] += dp[v][i];
    }
  }
  long long sum = 0;
  for (auto &v : adj[u]) {
    if (v == p) continue;
    for (int i = 1; i < k; ++i) {
      sum += dp[v][i - 1] * (dp[u][k - i] - dp[v][k - i - 1]);
    }
  }
  ans += dp[u][k] + sum / 2;
}
int main() {
  run();
  cin >> n >> k;
  for (int i = 0; i < (int)(n - 1); ++i) {
    int u, v;
    cin >> u >> v;
    adj[v].push_back(u);
    adj[u].push_back(v);
  }
  dfs(1, -1);
  cout << ans;
}
