#include <bits/stdc++.h>
#define maxn 100001

using namespace std;

int n, k;
vector<int> adj[maxn];
int s[maxn], xoa[maxn], Pr[maxn];
int nho[maxn], cnt[maxn];
int d[maxn];
long long res;

void DFS (int u, int dad) {
    cnt[d[u]]++;
    for (int v : adj[u])
        if (!xoa[v] && v != dad) {
            d[v] = d[u] + 1;
            DFS (v, u);
        }
}

void DFS_size (int u, int dad) {
    s[u] = 1;
    for (int v : adj[u])
        if (v != dad && !xoa[v]) {
            Pr[v] = u;
            DFS_size (v, u);
            s[u] += s[v];
        }
}

void Centroid_decompose (int r, int dad) {
    Pr[r] = 0;
    DFS_size (r, 0);
    int siz = s[r], smax;
    while (1) {
        smax = siz - s[r];
        int u = 0;
        for (int v : adj[r])
            if (!xoa[v]) {
                if (Pr[v] == r && smax < s[v]) {
                    smax = s[v];
                    u = v;
                }
            }
        if (smax <= siz / 2)
            break;
        r = u;
    }


    // Dem so luong duong di do dai k qua goc r
    for (int l = 0; l <= min (siz, k); ++l)
        nho[l] = 0;
    for (int v : adj[r])
        if (!xoa[v]) {
            for (int l = 0; l <= min (siz, k); ++l)
                cnt[l] = 0;
            d[v] = 1;

            DFS (v, r);
            if (siz >= k)
                res += cnt[k];
            for (int l = 1; l <= min (siz, k - 1); ++l)
                res += (k - l <= siz) ? 1LL * cnt[l] * nho[k - l] : 0;
            for (int l = 1; l <= min (siz, k); ++l)
                nho[l] += cnt[l];
        }


    // Xoay cay
    xoa[r] = 1;
    for (int u : adj[r])
        if (!xoa[u]) {
            Centroid_decompose (u, r);
        }
}

#define task "KPATH"
int main() {

    if (fopen(task".inp","r")) {
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
    ios::sync_with_stdio (0);
    cin.tie (0);
    cout.tie (0);

    cin >> n >> k;
    for (int i = 1; i < n; ++i) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back (v);
        adj[v].push_back (u);
    }

    res = 0;
    Centroid_decompose (1, 0);

    cout << res;
}