#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,n) for(int i=0;i<n;++i)

template<class T> inline void print(const T & a) { cout << a << "\n"; }
template<class T, class... Ts> inline void print(const T & a, const Ts&... ts) { cout << a << " "; print(ts...); }
template<class T> inline void print(const vector<T>&v) { for (int i = 0; i < v.size(); ++i)cout << v[i] << (i == v.size() - 1 ? "\n" : " "); }

pair<int, int> operator+(const pair<int, int>& a, const pair<int, int>& b) {
    return { a.first + b.first,a.second + b.second };
}
pair<int, int> operator-(const pair<int, int>& a, const pair<int, int>& b) {
    return { a.first - b.first,a.second - b.second };
}
pair<int, int> operator+=(pair<int, int>& a, const pair<int, int>& b) {
    a.first += b.first;
    a.second += b.second;
    return a;
}

template<class T> class BinaryIndexedTree {
    int n;
    vector<T> dat;
public:
    BinaryIndexedTree(int n) : n(n), dat(n + 1) {};
    void add(int i, T a) {
        for (++i; i <= n; i += i & -i)dat[i] += a;
    }
    T sum(int r) {// sum of [0,r)
        T res = {};
        for (; r; r -= r & -r)res += dat[r];
        return res;
    }
    T sum(int l, int r) {// sum of [l,r)
        if (l < 0 || n < r || l > r)return {};
        return sum(r) - sum(l);
    }
};

int main() {
    int n; cin >> n;
    vector<vector<pair<int, int>>> g(n);
    rep(i, n - 1) {
        int a, b, c; cin >> a >> b >> c;
        --a, --b;
        g[a].emplace_back(b, c);
        g[b].emplace_back(a, c);
    }

    int now = 0;
    vector<int> siz(n, 1), x(n), in(n), out(n);
    auto dfs0 = [&](auto&& f, int cur, int par)->void {
        in[cur] = now;
        ++now;
        for (auto [to, weight] : g[cur]) {
            if (to == par)continue;
            x[to] = x[cur] ^ weight;
            f(f, to, cur);
            siz[cur] += siz[to];
        }
        out[cur] = now;
    };
    dfs0(dfs0, 0, -1);

    auto sorted_x = x;

    sort(sorted_x.begin(), sorted_x.end());
    sorted_x.erase(unique(sorted_x.begin(), sorted_x.end()), sorted_x.end());
    rep(i, n)x[i] = lower_bound(sorted_x.begin(), sorted_x.end(), x[i]) - sorted_x.begin();//compress

    vector<vector<int>> idxs(sorted_x.size());
    auto dfs1 = [&](auto&& f, int cur, int par)->void {
        idxs[x[cur]].push_back(in[cur]);
        for (auto [to, weight] : g[cur]) {
            if (to == par)continue;
            f(f, to, cur);
        }
    };
    dfs1(dfs1, 0, -1);
    vector<BinaryIndexedTree<pair<int, int>>> y_cnt;
    y_cnt.reserve(idxs.size());
    rep(i, idxs.size()) {
        sort(idxs[i].begin(), idxs[i].end());
        y_cnt.emplace_back(idxs[i].size());
    }

    ll ans = ll(n) * (n - 1);
    auto dfs2 = [&](auto&& f, int cur, int par)->void {
        int l = lower_bound(idxs[x[cur]].begin(), idxs[x[cur]].end(), in[cur]) - idxs[x[cur]].begin();
        int r = lower_bound(idxs[x[cur]].begin(), idxs[x[cur]].end(), out[cur]) - idxs[x[cur]].begin();
        for (auto [to, weight] : g[cur]) {
            if (to == par)continue;
            f(f, to, cur);
        }


        {
            auto [y, cnt] = y_cnt[x[cur]].sum(l, r);
            ans -= y;//case-1
            y_cnt[x[cur]].add(l, pair<int, int>(siz[cur] - y, 1 - cnt));
        }

        if (cur == 0) {
            rep(i, idxs.size())if (i != x[cur]) {
                auto [y, cnt] = y_cnt[i].sum(0, idxs[i].size());
                ans -= ll(y) * cnt;//case-3
            }
        }
        else {
            l = lower_bound(idxs[x[par]].begin(), idxs[x[par]].end(), in[cur]) - idxs[x[par]].begin();
            r = lower_bound(idxs[x[par]].begin(), idxs[x[par]].end(), out[cur]) - idxs[x[par]].begin();
            auto [y, cnt] = y_cnt[x[par]].sum(l, r);
            ans -= ll(cnt) * (n - siz[cur]);//case-2
            ans -= ll(y) * cnt;//case-3

            ans += siz[cur];//case-3
        }
    };
    dfs2(dfs2, 0, -1);
    cout << ans << "\n";

    return 0;
}