#include <bits/stdc++.h>
using namespace std;
long long cnt0, cnt1, k, n, ans;
long long parent[50004];
long long dp[50005][505];
vector<vector<long long> > tree(50005);
void DFS(long long v, long long p) {
  parent[v] = p;
  dp[v][0] = 1;
  for (long long i = 0; i < tree[v].size(); i++) {
    long long to = tree[v][i];
    if (to == p) continue;
    DFS(to, v);
    for (long long j = 0; j < k; j++) dp[v][j + 1] += dp[to][j];
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> k;
  for (long long i = 1; i < n; i++) {
    long long a, b;
    cin >> a >> b;
    tree[a].push_back(b);
    tree[b].push_back(a);
  }
  DFS(1ll, 0ll);
  for (long long i = 1; i <= n; i++) {
    long long j = i;
    long long counter = k;
    long long t = 0;
    while (parent[j] != 0 && counter >= 0) {
      counter--;
      t++;
      if (counter == 0) {
        cnt0++;
        break;
      } else {
        cnt1 += (dp[parent[j]][k - t] - dp[j][k - t - 1]);
      }
      j = parent[j];
    }
  }
  ans = cnt1 / 2ll + cnt0;
  cout << ans;
  return 0;
}
