#include <bits/stdc++.h>
using namespace std;
vector<int> v[50005];
int b[50005][505];
int dfs(int u, int pu, int par[]) {
  par[u] = pu;
  int i;
  for (i = 0; i < v[u].size(); i++) {
    if (v[u][i] != pu) {
      dfs(v[u][i], u, par);
    }
  }
  return 1;
}
int createArray(int u, int k, int pu) {
  if (k == 0) {
    b[u][k] = 1;
    return 1;
  } else if (v[u].size() == 1 && v[u][0] == pu) {
    b[u][k] = 0;
    return 0;
  } else if (b[u][k] != -1)
    return b[u][k];
  else {
    int i, sum = 0;
    for (i = 0; i < v[u].size(); i++) {
      if (v[u][i] != pu) {
        sum += createArray(v[u][i], k - 1, u);
      }
    }
    return b[u][k] = sum;
  }
}
long long nway(int u, int k, int pu) {
  int i, j;
  long long sum = 0;
  for (i = 0; i < v[u].size(); i++) {
    if (v[u][i] != pu) {
      for (j = 1; j <= k - 1; j++) {
        sum += (long long)b[v[u][i]][j - 1] *
               ((long long)b[u][k - j] - (long long)b[v[u][i]][k - j - 1]);
      }
    }
  }
  return sum / 2;
}
int main() {
  int n, i, j, p, q, k;
  scanf("%d", &n);
  scanf("%d", &k);
  for (i = 0; i < n - 1; i++) {
    scanf("%d", &p);
    scanf("%d", &q);
    v[p].push_back(q);
    v[q].push_back(p);
  }
  int par[n + 5];
  dfs(1, 0, par);
  for (i = 0; i < 50005; i++) {
    for (j = 0; j < 505; j++) {
      b[i][j] = -1;
    }
  }
  for (i = 1; i <= n; i++) {
    for (j = 0; j <= k; j++) {
      createArray(i, j, par[i]);
    }
  }
  long long sum = 0;
  for (i = 1; i <= n; i++) {
    sum += nway(i, k, par[i]);
    sum += (long long)b[i][k];
  }
  cout << sum << "\n";
  return 0;
}
