#include <bits/stdc++.h>
using namespace std;
const int INF = 1 << 29;
const double EPS = 1e-10;
vector<int> G[50010];
vector<int> chil[50010];
int cnt[50010][510];
void dfs(int pos, int par) {
  for (int i = 0; i < (int)G[pos].size(); i++) {
    if (G[pos][i] != par) {
      chil[pos].push_back(G[pos][i]);
      dfs(G[pos][i], pos);
    }
  }
}
void init(int n) {
  memset(cnt, 0, sizeof(cnt));
  dfs(0, -1);
}
void calc(int v, int k, long long &sum) {
  for (int i = 0; i < (int)chil[v].size(); i++) {
    int c = chil[v][i];
    calc(c, k, sum);
    for (int j = 0; j < k; j++) {
      sum += (long long)cnt[c][j] * cnt[v][k - j - 1];
    }
    for (int j = 0; j < k; j++) {
      cnt[v][j + 1] += cnt[c][j];
    }
  }
  cnt[v][0] = 1;
  sum += (long long)cnt[v][0] * cnt[v][k];
}
int main() {
  int n, k, a, b;
  cin >> n >> k;
  for (int i = 0; i < n - 1; i++) {
    cin >> a >> b;
    a--, b--;
    G[a].push_back(b);
    G[b].push_back(a);
  }
  init(n);
  long long res = 0;
  calc(0, k, res);
  cout << res << endl;
  return 0;
}
