#include <bits/stdc++.h>
using namespace std;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
long long powmod(long long a, long long b, long long mod) {
  if (b == 0 || a == 1) {
    if (mod == 1)
      return 0;
    else
      return 1;
  }
  if (b % 2 == 0) {
    long long k = powmod(a, b / 2, mod);
    return (k * k) % mod;
  } else {
    long long k = powmod(a, b / 2, mod);
    return ((k * k) % mod * a) % mod;
  }
}
long long gcd(long long a, long long b) {
  if (a == 0) return b;
  if (b == 0) return a;
  if (a > b)
    return gcd(a % b, b);
  else
    return gcd(b % a, a);
}
long long prime(long long p) {
  for (long long i = 2; i * i <= p; i++) {
    if (p % i == 0 && i < p) return i;
  }
  return 1;
}
long long inv(long long a, long long mod) { return powmod(a, mod - 2, mod); }
long long random_modul() {
  uniform_int_distribution<long long> u1(1e9, 2e9);
  long long pepega = u1(rnd);
  while (prime(pepega) != 1) pepega = u1(rnd);
  return pepega;
}
vector<bool> used;
vector<vector<long long>> dp;
vector<vector<long long>> g;
long long a, k;
long long ans;
void dfs(long long v) {
  used[v] = true;
  dp[v][0] = 1;
  for (long long j = 0; j < g[v].size(); j++) {
    if (!used[g[v][j]]) {
      used[g[v][j]] = true;
      dfs(g[v][j]);
      for (long long u = 0; u < k; u++) {
        ans += dp[g[v][j]][u] * dp[v][k - u - 1];
      }
      for (long long u = 0; u < k; u++) dp[v][u + 1] += dp[g[v][j]][u];
    }
  }
  return;
}
void solve() {
  cin >> a >> k;
  g.resize(a);
  dp.resize(a);
  for (long long i = 0; i < a; i++) dp[i].resize(k + 1);
  used.resize(a);
  for (long long i = 0; i < a - 1; i++) {
    long long x, y;
    cin >> x >> y;
    x--;
    y--;
    g[x].push_back(y);
    g[y].push_back(x);
  }
  dfs(0);
  for (long long i = 0; i < a; i++) {
  }
  cout << ans;
  return;
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long tututu;
  tututu = 1;
  for (long long qwerty = 0; qwerty < tututu; qwerty++) solve();
  return 0;
}
