#include #include #include #include #include #include #include #include #define rep(i, a, b) for (int i = int(a); i < int(b); i++) using namespace std; using ll = long long int; // NOLINT using P = pair; // clang-format off #ifdef _DEBUG_ #define dump(...) do{ cerr << __LINE__ << ":\t" << #__VA_ARGS__ << " = "; debug_print(__VA_ARGS__); } while(false) template void debug_print(const T &t, const Ts &...ts) { cerr << t; ((cerr << ", " << ts), ...); cerr << endl; } #else #define dump(...) do{ } while(false) #endif template vector make_v(size_t a, T b) { return vector(a, b); } template auto make_v(size_t a, Ts... ts) { return vector(a, make_v(ts...)); } template bool chmin(T &a, const T& b) { if (a > b) {a = b; return true; } return false; } template bool chmax(T &a, const T& b) { if (a < b) {a = b; return true; } return false; } template void print(const T& t, const Ts&... ts) { cout << t; ((cout << ' ' << ts), ...); cout << '\n'; } template void input(Ts&... ts) { (cin >> ... >> ts); } template istream &operator,(istream &in, T &t) { return in >> t; } struct Inf { template constexpr operator T() { return numeric_limits::max() / 2; } }; // clang-format on template class ModInt { ll n; auto constexpr inverse() const { return this->pow(*this, this->mod - 2); } public: constexpr static ll mod = MOD; using mint = ModInt; constexpr ModInt() : n(0) {} constexpr ModInt(const ll &nn) : n(((nn % MOD) + MOD) % MOD) {} constexpr mint operator+=(const mint &m) { n += m.n; if (n >= mint::mod) n -= mint::mod; return *this; } constexpr mint operator-=(const mint &m) { n -= m.n; if (n < 0) n += mint::mod; return *this; } constexpr mint operator*=(const mint &m) { n *= m.n; if (n >= mint::mod) n %= mint::mod; return *this; } constexpr mint operator/=(const mint &m) { return (*this) *= m.inverse(); } friend constexpr mint operator+(mint t, const mint &m) { return t += m; } friend constexpr mint operator-(mint t, const mint &m) { return t -= m; } friend constexpr mint operator*(mint t, const mint &m) { return t *= m; } friend constexpr mint operator/(mint t, const mint &m) { return t /= m; } constexpr mint operator=(const ll &l) { n = l % mint::mod; if (n < 0) n += mint::mod; return *this; } friend ostream &operator<<(ostream &out, const mint &m) { out << m.n; return out; } friend istream &operator>>(istream &in, mint &m) { ll l; in >> l; m = l; return in; } static constexpr auto pow(const mint &x, ll p) { mint ans = 1; for (auto m = x; p > 0; p /= 2, m *= m) { if (p % 2) ans *= m; } return ans; } constexpr ll get_raw() const { return n; } }; using mint = ModInt<1000000007>::mint; constexpr mint operator"" _m(unsigned long long m) { return mint(m); } class UnionFind { public: vector par; int N; UnionFind(int n) { par.resize(n, -1); N = n; } int Find(int n) { return par[n] < 0 ? n : par[n] = Find(par[n]); } bool Union(int x, int y) { x = Find(x); y = Find(y); if (x == y) return false; if (-par[x] > -par[y]) swap(x, y); par[y] += par[x]; par[x] = y; N--; return true; } bool Same(int x, int y) { return Find(x) == Find(y); } int size(int x) { return -par[Find(x)]; } int size() { return N; } }; using Edge = tuple; int main() { cin.tie(nullptr); ios::sync_with_stdio(false); int n; cin >> n; vector edges; rep(i, 0, n - 1) { int a, b, c; cin >> a >> b >> c; a--; b--; edges.emplace_back(a, b, c); } mint div2 = 1_m / 2; mint ans = 0; rep(bit, 0, 33) { UnionFind uf(n); for (auto [a, b, c] : edges) { if ((c >> bit) & 1) uf.Union(a, b); } vector used(n, false); mint masked = 1LL << bit; rep(i, 0, n) { int p = uf.Find(i); if (used[p]) continue; used[p] = true; ll s = uf.size(p); ans += 1_m * s * (s - 1) * div2 * masked; } } print(ans); return 0; }