#include #define _GLIBCXX_DEBUG using namespace std; using ll = long long; using V = vector; using VV = vector; #define rep2(i, m, n) for (int i = (m); i < (n); ++i) #define drep2(i, m, n) for (int i = (m)-1; i >= (n); --i) #define rep(i, n) rep2(i, 0, n) #define drep(i, n) drep2(i, n, 0) struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_; const int MOD = int(1e9)+7; struct mint { ll x; mint(ll x=0) : x(x%MOD) {} mint& operator+=(const mint a) { if ((x += a.x) >= MOD) x -= MOD; return *this; } mint& operator*=(const mint a) { (x *= a.x) %= MOD; return *this; } mint operator+(const mint a) const { return mint(*this) += a; } mint operator*(const mint a) const { return mint(*this) *= a; } mint pow(ll t) const { if (!t) return 1; mint a = pow(t>>1); a *= a; if (t&1) a *= *this; return a; } }; ostream& operator<<(ostream& os, const mint& a) { return os << a.x; } using Vm = vector; VV G; Vm dfs(int k, int u, int p=-1) { Vm res = {1, 1, 0, 0}; for (int v : G[u]) if (v != p) { auto q = dfs(k, v, u); q[0] *= 2; q[k] *= 2; drep(i, 4) { res[i] *= q[0]; rep2(j, 1, i+1) res[i] += res[i-j] * q[j]; } } return res; } int main() { int n; cin >> n; G.assign(n, V()); rep(i, n-1) { int u, v; cin >> u >> v; --u, --v; G[u].push_back(v); G[v].push_back(u); } auto dp1 = dfs(1, 0); auto dp2 = dfs(2, 0); auto dp3 = dfs(3, 0); mint ans = mint(2).pow(n-1) * n; ans += dp2[2] * 6; ans += dp3[3] * 6; cout << ans << '\n'; return 0; }