#include <bits/stdc++.h>
using namespace std;
int func[50010][520];
void dfs(int u, int p, vector<int> adjlist[], vector<int> &parent,
         vector<bool> visited, int k) {
  parent[u] = p;
  visited[u] = true;
  for (int j = 0; j < adjlist[u].size(); j++) {
    int v = adjlist[u][j];
    if (!visited[v] && v != u) {
      dfs(v, u, adjlist, parent, visited, k);
      for (int i = k; i >= 1; i--) func[u][i] += func[v][i - 1];
    }
  }
  func[u][0] = 1;
  return;
}
int main() {
  ios_base::sync_with_stdio(false);
  int n, k;
  cin >> n >> k;
  vector<int> adjlist[n + 1], parent(n + 1, -1);
  vector<bool> visited(n + 1, false);
  for (int i = 1; i <= n - 1; i++) {
    int a, b;
    cin >> a >> b;
    adjlist[a].push_back(b);
    adjlist[b].push_back(a);
  }
  dfs(1, -1, adjlist, parent, visited, k);
  long long ans = 0;
  for (int i = 1; i <= n; i++) {
    ans += func[i][k];
    long long val = 0;
    for (auto v : adjlist[i]) {
      if (v != parent[i]) {
        for (int j = 0; j <= k - 2; j++)
          val += func[v][j] * (func[i][k - j - 1] - func[v][k - j - 2]);
      }
    }
    ans += (val / 2);
  }
  cout << ans << "\n";
}
