#include <bits/stdc++.h>
using namespace std;
bool isPrime(long long int n) {
  if (n <= 1) return false;
  if (n <= 3) return true;
  if (n % 2 == 0 || n % 3 == 0) return false;
  for (long long int i = 5; i * i <= n; i = i + 6)
    if (n % i == 0 || n % (i + 2) == 0) return false;
  return true;
}
vector<int> gr[50005];
int n, k;
bool vis[50005];
int lev[50005][505];
long long int dp[50005];
void dfs(int v) {
  vis[v] = true;
  lev[v][0] = 1;
  for (auto ed : gr[v]) {
    if (!vis[ed]) {
      dfs(ed);
      for (long long int i = 1; i < k + 1; i++) lev[v][i] += lev[ed][i - 1];
    }
  }
}
void solve(int v) {
  vis[v] = true;
  for (auto ed : gr[v]) {
    if (!vis[ed]) {
      solve(ed);
      for (long long int i = 1; i < k; i++)
        dp[v] += lev[ed][i - 1] * (lev[v][k - i] - lev[ed][k - i - 1]);
    }
  }
  dp[v] /= 2;
  dp[v] += lev[v][k];
}
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> k;
  int a, b;
  for (long long int i = 0; i < n - 1; i++) {
    cin >> a >> b;
    gr[a].push_back(b);
    gr[b].push_back(a);
  }
  memset(lev, 0, sizeof(lev));
  memset(vis, false, sizeof(vis));
  dfs(1);
  memset(vis, false, sizeof(vis));
  memset(dp, 0, sizeof(dp));
  solve(1);
  long long int ans = 0;
  for (long long int i = 1; i < n + 1; i++) ans += dp[i];
  cout << ans;
}
