#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using i2 = pair<int, int>;
const int N = 5e4 + 9;
vector<int> adj[N];
ll dp1[N][501], dp2[N];
void dfs(int u, int p, int k) {
  int c = 0;
  dp1[u][0] = 1;
  for (int v : adj[u]) {
    if (v != p) {
      dfs(v, u, k);
      c++;
      for (int i = 1; i <= k; i++) dp1[u][i] += dp1[v][i - 1];
    }
  }
  if (c >= 2) {
    for (int v : adj[u]) {
      if (v != p) {
        for (int i = 0; i <= k - 2; i++)
          dp2[u] += dp1[v][i] * (dp1[u][k - i - 1] - dp1[v][k - i - 2]);
      }
    }
    dp2[u] /= 2;
  }
  dp2[u] += dp1[u][k];
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n, k;
  cin >> n >> k;
  for (int i = 1; i < n; i++) {
    int a, b;
    cin >> a >> b;
    adj[a].push_back(b);
    adj[b].push_back(a);
  }
  if (k == 1) {
    cout << n - 1;
    return 0;
  }
  dfs(1, 0, k);
  int res = 0;
  for (int i = 1; i <= n; i++) res += dp2[i];
  cout << res;
  return 0;
}
