#include <bits/stdc++.h>
#define ll long long
#define MODV 1000000007
#define INFLL LLONG_MAX // 9223372036854775807
#define EPS 1e-9
#define rep(i, n) for(ll i=0, i##_len=(ll)(n); i<i##_len; i++)
#define repf(i, n) for(ll i=1, i##_len=(ll)(n+1); i<i##_len; i++)
#define all(v) v.begin(), v.end()
#define endl "\n"
#define vi vector<ll>
#define vvi vector<vector<ll>>
#define Yes() cout << "Yes" << endl
#define YES() cout << "YES" << endl
#define No() cout << "No" << endl
#define NO() cout << "NO" << endl
#define Init() std::ios::sync_with_stdio(false); std::cin.tie(0); std::cout<<fixed<<setprecision(15);
template<class T>bool chmax(T &a, const T &b){ if(a<b){ a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b){ if(b<a){ a=b; return 1; } return 0; }
using namespace std;

template<int MOD> struct Fp{
    long long val;
    constexpr Fp(long long v = 0) noexcept : val(v % MOD){ if(val<0) v += MOD; }
    constexpr int getmod(){ return MOD; }
    constexpr Fp operator - () const noexcept{ return val ? MOD - val : 0; }
    constexpr Fp operator + (const Fp& r) const noexcept{ return Fp(*this) += r; }
    constexpr Fp operator - (const Fp& r) const noexcept{ return Fp(*this) -= r; }
    constexpr Fp operator * (const Fp& r) const noexcept{ return Fp(*this) *= r; }
    constexpr Fp operator / (const Fp& r) const noexcept{ return Fp(*this) /= r; }
    constexpr Fp& operator += (const Fp& r) noexcept{ val += r.val; if(val>=MOD) val -= MOD; return *this; }
    constexpr Fp& operator -= (const Fp& r) noexcept{ val -= r.val; if(val<0) val += MOD; return *this; }
    constexpr Fp& operator *= (const Fp& r) noexcept{ val = val*r.val%MOD; return *this; }
    constexpr Fp& operator /= (const Fp& r) noexcept{
        long long a = r.val, b = MOD, u = 1, v = 0;
        while (b) { long long t = a/b; a -= t*b; swap(a, b); u -= t*v; swap(u, v); }
        val = val*u%MOD; if(val<0) val += MOD; return *this; }
    constexpr bool operator == (const Fp& r) const noexcept{ return this->val == r.val; }
    constexpr bool operator != (const Fp& r) const noexcept{ return this->val != r.val; }
    friend constexpr ostream& operator << (ostream &os, const Fp<MOD>& x) noexcept{ return os << x.val; }
    friend constexpr istream& operator >> (istream &is, Fp<MOD>& x) noexcept{ return is >> x.val; }
    friend constexpr Fp<MOD> modpow(const Fp<MOD> &a, long long n) noexcept{
        if (n == 0) return 1; auto t = modpow(a, n/2); t = t*t; if(n & 1) t = t*a; return t; }
};
const int MOD = MODV;
using mint = Fp<MOD>;

struct Edge{
    // 始点, 終点, 重み, 最大量
    long long src, dst, weight, capacity;
    Edge(): src(0), dst(0), weight(0), capacity(0) {}
    Edge(long long s, long long d, long long w): src(s), dst(d), weight(w) {}
    Edge(long long s, long long d, long long w, long long c): src(s), dst(d), weight(w), capacity(c) {}
};

class Graph{
public:
    long long size;
    vector<vector<Edge>> node;
    Graph(long long n): size(n), node(n) {}
    // 無向辺の追加
    void addEdge(long long s, long long d, long long w = 1){
        node[s].emplace_back(s, d, w);
        node[d].emplace_back(d, s, w);
    }
    // 有向辺の追加
    void addArc(long long s, long long d, long long w = 1){
        node[s].emplace_back(s, d, w);
    }
    // ノードの追加
    void addNode(){
        size++;
        node.emplace_back();
    }
};

mint ans = 1;

void bfs(Graph &g, ll n, ll k, ll i){
    queue<pair<ll, ll>> que;
    que.push(make_pair(i, k));
    vector<ll> chk(n); chk[i] = 1;

    while(que.size()){
        auto front = que.front();
        que.pop();
        ll node = front.first;
        ll cnt = front.second;
        ans *= cnt;
        if(--cnt < (k-2)) cnt = k-2;
        for(auto &edge: g.node[node]){
            if(chk[edge.dst] == 1) continue;
            chk[edge.dst] = 1;
            que.push(make_pair(edge.dst, cnt));
            cnt--;
        }
    }
}

int main(){
    Init();
    ll n, k; cin >> n >> k;
    Graph g(n);
    rep(i, n-1){
        ll a, b; cin >> a >> b;
        a--; b--;
        g.addEdge(a, b, 1);
    }
    bfs(g, n, k, 0);
    cout << ans << endl;
}

Measured memory_bytes: 15800