#include using namespace std; struct iofast_t { iofast_t() { ios::sync_with_stdio(false); cin.tie(nullptr); } } iofast; struct uns_t {} uns; template auto vec(Element init, Head arg, Args ...args) { if constexpr (sizeof...(Args) == 0) return vector(arg, init); else return vector(arg, vec(init, args...)); } template auto vec(uns_t, Head arg, Args ...args) { return vec(Element(), arg, args...); } template auto distance(const Container &c, decltype(begin(c)) iter) { return distance(begin(c), iter); } template ::value_type>> auto isort(RIter first, RIter last, Compare comp = Compare()) { vector i(distance(first, last)); iota(begin(i), end(i), 0); sort(begin(i), end(i), [&](auto x, auto y) { return comp(*(first + x), *(first + y)); }); return i; } template typename, typename = void_t<>> struct detect : false_type {}; template typename Check> struct detect>> : true_type {}; template typename Check> constexpr inline bool detect_v = detect::value; template using has_member_sort = decltype(declval().sort()); template > auto sorted(Container c, Compare comp = Compare()) { if constexpr (detect_v) { c.sort(comp); return c; } else { sort(begin(c), end(c), comp); return c; } } template > auto uniqued(Container c, Compare comp = Compare()) { c.erase(unique(begin(c), end(c), comp), end(c)); return c; } template > T &chmin(T &l, T r, Compare &&f = less()) { return l = min(l, r, f); } template > T &chmax(T &l, T r, Compare &&f = less()) { return l = max(l, r, f); } #include #include using mint = atcoder::modint1000000007; int main() { constexpr auto log2 = 30; int n; cin >> n; auto e = vec>(uns, n - 1); for (auto &[a, b, c] : e) { cin >> a >> b >> c; --a; --b; } mint ans = 0; for (int i = 0; i < log2; ++i) { atcoder::dsu dsu(n); for (auto [a, b, c] : e) { if (c & (1 << i)) { dsu.merge(a, b); } } for (auto g : dsu.groups()) { if (size(g) == 1) { continue; } mint s = size(g); ans += s * (s - 1) / 2 * (1 << i); } } cout << ans.val() << endl; }