#include <bits/stdc++.h>
using namespace std;
const int MAX = 50050;
vector<int> e[MAX];
vector<int> ee[MAX];
int c[MAX][555];
int vis[MAX];
int n, k;
void solve(int indx) {
  c[indx][0] = 1;
  vis[indx] = 1;
  for (int i = 0; i < e[indx].size(); i++) {
    if (vis[e[indx][i]] == 1) continue;
    int cindx = e[indx][i];
    ee[indx].push_back(cindx);
    solve(cindx);
    for (int j = 0; j <= k; j++) {
      if (c[cindx][j] == 0) break;
      c[indx][j + 1] += c[cindx][j];
    }
  }
}
long long solve1() {
  long long ans = 0;
  for (int i = 1; i <= n; i++) {
    long long ret = 0;
    for (int j = 0; j < ee[i].size(); j++) {
      for (int K = 1; K < k; K++) {
        long long first = 0, second = 0;
        first = c[ee[i][j]][K - 1];
        second = c[i][k - K] - c[ee[i][j]][k - K - 1];
        ret += (first * second);
      }
    }
    ans += ret / 2;
    ans += c[i][k];
  }
  return ans;
}
int main() {
  cin >> n >> k;
  for (int i = 0; i < n - 1; i++) {
    int x, y;
    cin >> x >> y;
    e[x].push_back(y);
    e[y].push_back(x);
  }
  solve(1);
  cout << solve1() << endl;
}
