#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
int n, k;

vector<int> g[100100];
int sz[100100];
int lev[100100];
int mx[100100];
int u[100100];
vector<int> G;

void dfs(int v, int pa){
    sz[v] = 1;
    mx[v] = 0;
    lev[v] = lev[pa] + 1;
    for(int to: g[v]){
        if(u[to]) continue;
        if(to == pa) continue;
        dfs(to, v);
        mx[v] = max(mx[v], sz[to]);
        sz[v] += sz[to];
    }
    G.push_back(v);
}
int cnt[100100];
ll ans = 0;

void solve(int v){
    G.clear();
    dfs(v, 0);
    int C = -1;
    for(int to: G){
        if(C == -1) C = to;
        else if(max(mx[C], (int) G.size() - sz[C]) > max(mx[to], (int) G.size() - sz[to])){
            C = to;
        }
    }
    int D = G.size();
    cnt[0]++;
    lev[C] = 0;
    for(int to: g[C]){
        if(u[to]) continue;
        G.clear();
        dfs(to, C);
        for(int V: G){
            if(lev[V] <= k){
                ans += cnt[k-lev[V]];
            }
        }
        for(int V: G){
            cnt[lev[V]]++;
        }
    }
    for(int i = 0; i < D; i++) cnt[i] = 0;

    u[C] = 1;
    for(int to: g[C]){
        if(u[to]) continue;
        solve(to);
    }

}

int main(){
    scanf("%d%d", &n, &k);
    for(int i = 1, x, y;i < n; i++){
        scanf("%d%d", &x, &y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
    solve(1);
    cout << ans << "\n";
    return 0;
}