#include <bits/stdc++.h>

int main () {

    int n, maxK;
    std::cin >> n >> maxK;

    std::vector<std::vector<int>> edges(n);
    for (int i = 0; i < n - 1; ++i) {
        int u, v;
        std::cin >> u >> v;
        --u, --v;
        edges[u].push_back(v);
        edges[v].push_back(u);
    }

    std::vector<std::vector<int64_t>> dp(n, std::vector<int64_t>(maxK + 1, 0));

    auto dfs = [&](int cur, int dad, auto&& dfs) -> void {

        for (const auto nei : edges[cur])
            if (nei != dad)
                dfs(nei, cur, dfs);

        auto& dp1 = dp[cur];
        std::vector<int64_t> dp2(maxK + 1, 0);
        dp1[0] = 1;

        for (const auto nei : edges[cur]) {
            if (nei == dad)
                continue;

            std::fill(dp2.begin(), dp2.end(), 0);

            for (int k1 = maxK; k1 >= 0; --k1) {
                if (!dp1[k1])
                    continue;

                //we skip this nei -> so we get +1 blue
                if (k1 != maxK)
                    dp2[k1 + 1] += dp1[k1];

                for (int k2 = 0; k1 + k2 <= maxK; ++k2)
                    dp2[k1 + k2] += dp1[k1] * dp[nei][k2];
            }

            std::swap(dp1, dp2);
        }
    };

    dfs(0, -1, dfs);

    int64_t ans = 1;

    for (int cur = 0; cur < n; ++cur) {
        ans += std::accumulate(dp[cur].begin(), dp[cur].end(), 0LL);
        if (cur)
            ans -= dp[cur][maxK];
    }

    std::cout << ans << "\n";

    return 0;
}