#include <bits/stdc++.h>
using namespace std;
void fast() {
  ios::sync_with_stdio(0);
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
const long long MAXN = 5e4 + 5;
const long long k = 505;
long long dp[MAXN][k];
vector<long long> edg[MAXN];
long long ans = 0, ka, sumyd = 0;
void dfs(long long v, long long p) {
  dp[v][0] = 1;
  long long i, a, b, x, y;
  for (auto u : edg[v])
    if (u != p) {
      dfs(u, v);
      for (i = 0; i < k - 2; i++) dp[v][i + 1] += dp[u][i];
    }
  for (auto u : edg[v]) {
    if (u == p) continue;
    for (i = 1; i * 2 <= ka; i++) {
      a = i;
      b = ka - i;
      x = dp[u][a - 1];
      y = dp[v][b] - dp[u][b - 1];
      if (i * 2 == ka)
        sumyd += x * y;
      else
        ans += x * y;
    }
  }
  ans += dp[v][ka];
}
signed main() {
  long long n, i, a, b, j;
  cin >> n >> ka;
  for (i = 0; i < n - 1; i++) {
    cin >> a >> b;
    edg[a].push_back(b);
    edg[b].push_back(a);
  }
  dfs(1, 0);
  cout << ans + sumyd / 2 << '\n';
  return 0;
}
