#include <iostream>
#include <cstdio>
#include <vector>
#include <set>
#include <utility>
#include <algorithm>
using namespace std;

const int MAXN = 50100;
const int MAXK = 501;

int n, k;
vector<int> v[MAXN];
int a, b;

long long dp[MAXN][MAXK];
int p[MAXN];
bool vis[MAXN];

long long res;

void go(int u, int anc = -1) {
    vis[u] = true;
    p[u] = anc;
    for (int i = 0; i < (int)v[u].size(); i++) {
        if (!vis[v[u][i]]) {
            go(v[u][i], u);
            for (int j = 0; j < k; j++) {
                dp[u][j + 1] += dp[v[u][i]][j];
            }
        }
    }
    dp[u][0] = 1;
    return;
}

long long calc(int u) {
    long long ans = 0;
    for (int i = 0; i < (int)v[u].size(); i++) {
        if (v[u][i] == p[u])
            continue;

        for (int j = 1; j < k; j++) {
            ans += dp[v[u][i]][j - 1] * (dp[u][k - j] - dp[v[u][i]][k - j - 1]);
        }
    }
    //cerr << dp[u][k] << " ";
    ans >>= 1;
    return (ans + dp[u][k]);
}

int main() {
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    scanf("%d%d", &n, &k);
    for (int i = 0; i < n - 1; i++) {
        scanf("%d%d", &a, &b);
        a--, b--;
        v[a].push_back(b);
        v[b].push_back(a);
    }

    go(0);
    for (int i = 0; i < n; i++) {
        //cerr << calc(i) << " ";
        res += calc(i);
    }
    cout << res << endl;
}