// compile: make data
// run: time ./data < big.in 
#include <bits/stdc++.h>
using namespace std;
// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#ifdef LOCAL
#include <debug/codeforces.h>
#define debug(x...) _debug_print(#x, x);
#define Debug(x...) _debug_print_format(#x, x);
std::ifstream terminal("/dev/tty");
#define PP std::cerr<<"\033[1;30mpause...\e[0m",terminal.ignore();
#else
#define debug(x...)
#define Debug(x...)
#define PP
#endif
template<typename...Args> void print_(Args...args){((cout<<args<<" "),...)<<endl;}
#define VI vector<int>
#define VII vector<vector<int>>
#define VIII vector<vector<vector<int>>>
#define rep(i,a,b) for(int i=(a);i<(int)(b);++i)
#define sz(v) ((int)(v).size())
#define print(...) print_(__VA_ARGS__);
#define FIND(a, x) ((find(a.begin(),a.end(),(x))!=a.end())?1:0)
#define cmin(x,...) x=min({(x), __VA_ARGS__})
#define cmax(x,...) x=max({(x), __VA_ARGS__})
#define INTMAX (int)(9223372036854775807)
#define INF (int)(1152921504606846976)
#define NaN (int)(0x8b88e1d0595d51d1)
#define double long double
#define int long long
#define MAXN 200010
 
struct tree {
    int n;
    vector<vector<int>> e;
    struct node {
        vector<node*> ch;
        node *parent = nullptr;
        int size, depth, height;
    };
    vector<node> vertex;
    vector<int> removed;
    node *root;
    tree(int V) {
        n = V;
        e.resize(n);
        vertex.resize(n);
        removed.assign(n, 0);
    }
    void add_edge(int u, int v) {
        e[u].push_back(v), e[v].push_back(u);
    }
    int ind(node *x) {return x - &vertex[0]; }
    void setroot(int rt = 0) {
        if (root != &vertex[rt]) build(rt);
        root = &vertex[rt];
    }
    void build(int rt) {
        function<void(int, int)> dfs = [&](int u, int pre) {
            node *x = &vertex[u];
            x->size = 1;
            x->depth = !~pre ? 0 : x->parent->depth + 1;
            x->height = 1;
            x->ch.clear();
            for (int v: e[u]) {
                if (v == pre || removed[v]) continue;
                node *y = &vertex[v];
                x->ch.push_back(y);
                y->parent = x;
                dfs(v, u);
                x->size += y->size;
                cmax(x->height, y->height + 1);
            }
        };
        dfs(rt, -1);
    }
    int centroid(int r = -1) {
        if (~r) build(r);
        else r = ind(root);
        int N = vertex[r].size;
        if (N <= 2) return r;
        for (node *x = &vertex[r]; x; ) {
            int maxsz = -INF;
            node *maxnode = nullptr;
            for (auto y: x->ch) if (y->size > maxsz) maxsz = y->size, maxnode = y;
            if (maxsz <= N / 2) return ind(x);
            x = maxnode;
        }
        return r;
    }
    void centroid_decomp(auto solve) {
        auto getvs = [&](int u) -> vector<int> {
            vector<int> vs;
            queue<int> q; q.push(u);
            while (!q.empty()) {
                int x = q.front(); q.pop();
                vs.push_back(x);
                for (auto y: vertex[x].ch) q.push(ind(y));
            }
            return vs;
        };
        function<void(node*)> dfs = [&](node *x) -> void {
            int c = centroid(ind(x));
            if(c != ind(x)) build(c);
            vector<vector<int>> vs;
            for (auto y: vertex[c].ch) vs.push_back(getvs(ind(y)));
            solve(c, vs);
            removed[c] = 1, vertex[c].ch.clear();
            for (auto v: e[c]) if (!removed[v]) dfs(&vertex[v]);
        };
        dfs(root);
    }
    // void graphviz_dump(int plus = 0, string filename = "graph.dot") {
    //     string vlabel = "", elabel = "";
    //     // vlabel = " color=\"red\"";
    //     // elabel = " color=\"red\"";
    //     set<int> vset; set<pair<int, int>> eset;
    //     rep(i, 0, n) if (vertex[i].heavy) vset.insert(ind(vertex[i].heavy)), eset.insert({i, ind(vertex[i].heavy)});
    //     FILE *f = fopen(filename.c_str(), "w");
    //     fprintf(f, "digraph Tree {\n");
    //     rep(i, 0, n) {
    //         node *x = &vertex[i];
    //         fprintf(f, "    %lld;\n", vset.count(i) ? vlabel.c_str() : "");
    //     }
    //     rep(i, 0, n) {
    //         node *x = &vertex[i];
    //         for (auto y: x->ch) {
    //             fprintf(f, "    %ld -> %ld[arrowhead=\"none\"%s];\n", x - &vertex[0], y - &vertex[0], eset.count({i, ind(y)}) ? elabel.c_str() : "");
    //         }
    //     }
    //     fprintf(f, "}\n");
    // }
};
 
int32_t main() {
    ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
 
    int n, k; cin >> n >> k;
    tree g(n);
    rep(i, 0, n-1) {
        int u, v; cin >> u >> v; --u, --v;
        g.add_edge(u, v);
    }
    g.setroot(0);
    int answer = 0;
    auto solve = [&](int root, vector<vector<int>>& subtrees) -> void {
        auto getans = [](vector<int> &hs, int k) -> int {
            int ans = 0;
            for (int i = 0; i < sz(hs) && k-i>=i; ++i) {
                if (k-i < 0 || k-i >= sz(hs)) continue;
                ans += i==k-i ? (hs[i] * (hs[k-i]-1))/2 : hs[i] * hs[k-i];
            }
            return ans;
        };
        vector<int> cnt = {1};
        int minus = 0;
        for (auto &vs: subtrees) {
            vector<int> cur;
            for (auto i: vs) {
                int d = g.vertex[i].depth;
                if (d >= sz(cur)) cur.resize(d+1);
                ++cur[d];
            }
            minus += getans(cur, k);
            if (sz(cur) > sz(cnt)) cnt.resize(sz(cur));
            rep(i, 0, sz(cur)) cnt[i] += cur[i];
        }
        answer += getans(cnt, k) - minus;
    };
    g.centroid_decomp(solve, k);
    cout << answer << endl;
 
    return 0;
}