#include<bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define popb pop_back
#define popf pop_front
#define ins insert
#define pq priority_queue
#define minele min_element
#define maxele max_element
#define lb lower_bound //first pos >= val
#define ub upper_bound // first pos > val
#define cnt_bit __builtin_popcount
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
using namespace std;

typedef unsigned long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;

int d4x[4] = {1, 0, -1, 0}; int d4y[4] = {0, 1, 0, -1};
int d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};

const ll oo = 1e18;
const ll maxN = 1e6;

const int LOG = 30;
const int N = 1e5 + 2710;
vector<pii> g[N];
vector<int> son[N];
int sz[N];
ll cnt[LOG + 5][2];
int child[N];
ll num[N];
ll ans = 0;

void dfs_sub1(int u, int par, ll val) {
    ans += val;
    for(pii v : g[u]) {
        if(v.fi != par) {
            dfs_sub1(v.fi, u, val ^ v.se);
        }
    }
}

void sub1(int n) {
    for(int i = 1; i < n; i++) {
        int u, v, L;
        cin >> u >> v >> L;
        g[u].pb(make_pair(v, L)); g[v].pb(make_pair(u, L));
    }

    for(int i = 1; i <= n; i++) {
        dfs_sub1(i, 0, 0);
    }

    cout << ans / 2;
}

void dfssz(int u, int par) {
    sz[u] = 1;
    for(pii v : g[u]) {
        if(v.fi != par) {
            num[v.fi] = num[u] ^ v.se;
            dfssz(v.fi, u);
            sz[u] += sz[v.fi];
        }
    }
}

void dfs(int u, int par, bool isBig) {
    int big = 0; ll ed = 0;
    for(pii v : g[u]) {
        if(v.fi != par && sz[v.fi] > sz[big]) big = v.fi, ed = v.se;
    }

    for(pii v : g[u]) {
        if(v.fi != par && v.fi != big) dfs(v.fi, u, false);
    }

    if(big > 0) {
        dfs(big, u, true);
        swap(son[u], son[big]);
    }

    for(int i = 0; i <= LOG; i++) {
        int p = (ed >> i & 1);
        if(p > 0) swap(cnt[i][0], cnt[i][1]);
        ans += 1ll * (1ll << i) * cnt[i][1];
        ++cnt[i][0];
    }

    son[u].pb(u);

    for(pii v : g[u]) {
        if(v.fi != par && v.fi != big) {
            int iter = 0;
            for(auto c : son[v.fi]) {
                ll curr = num[c] ^ num[u];
                for(int i = 0; i <= LOG; i++) {
                    int p = (curr >> i & 1);
                    ans += 1ll * (1ll << i) * cnt[i][p ^ 1];
                }

                child[++iter] = c;
            }

            for(int i = 1; i <= iter; i++) {
                son[u].pb(child[i]);
                ll curr = num[child[i]] ^ num[u];
                for(int j = 0; j <= LOG; j++) {
                    int p = (curr >> j & 1);
                    ++cnt[j][p];
                }
            }
        }
    }

//  cout << debug(u) debug(ans) << endl;
//  for(int i = 0; i <= 3; i++) {
//      cout << debug(i) debug(cnt[i][0]) debug(cnt[i][1]) << endl;
//  }

    if(!isBig) {
        for(int i = 0; i <= LOG; i++) cnt[i][0] = cnt[i][1] = 0;
    }
}

void sub3(int n) {
    for(int i = 1; i < n; i++) {
        int u, v, L;
        cin >> u >> v >> L;
        g[u].pb(make_pair(v, L)); g[v].pb(make_pair(u, L));
    }

    dfssz(1, 0);
    dfs(1, 0, 1);
    cout << ans;
}

void solve() {
    int n; cin >> n;
    if(n <= 3000) {
        sub1(n);
        return;
    }

    //DSU ON TREE
    sub3(n);
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    //freopen("XTREEW.inp", "r", stdin);
    //freopen("XTREEW.out", "w", stdout);
    solve();
}