#include <bits/stdc++.h>
 
//#include <unistd.h>
//#include <iostream>
 
using namespace std;
 
#define DEBUG(x) cerr<<#x<<": "<<x<<endl;
#define DEBUG_VEC(v) cerr<<#v<<":";for(int i=0;i<v.size();i++) cerr<<" "<<v[i]; cerr<<endl;
#define DEBUG_MAT(v) cerr<<#v<<endl;for(int i=0;i<v.size();i++){for(int j=0;j<v[i].size();j++) {cerr<<v[i][j]<<" ";}cerr<<endl;}
typedef long long ll;
#define int ll
 
#define vi vector<int>
#define vl vector<ll>
#define vii vector< vector<int> >
#define vll vector< vector<ll> >
#define vs vector<string>
#define pii pair<int,int>
#define pis pair<int,string>
#define psi pair<string,int>
#define pll pair<ll,ll>
template<class S, class T> pair<S, T> operator+(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first + t.first, s.second + t.second); }
template<class S, class T> pair<S, T> operator-(const pair<S, T> &s, const pair<S, T> &t) { return pair<S, T>(s.first - t.first, s.second - t.second); }
template<class S, class T> ostream& operator<<(ostream& os, pair<S, T> p) { os << "(" << p.first << ", " << p.second << ")"; return os; }
#define X first
#define Y second
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep1(i,n) for(int i=1;i<=(n);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrep1(i,n) for(int i=(n);i>0;i--)
#define REP(i,a,b) for(int i=a;i<b;i++)
#define in(x, a, b) (a <= x && x < b)
#define all(c) c.begin(),c.end()
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a = b; return 1; } return 0; }
#define UNIQUE(v) v.erase(std::unique(v.begin(), v.end()), v.end());
const ll inf = 1000000001;
const ll INF = (ll)1e18 + 1;
const long double pi = 3.1415926535897932384626433832795028841971L;
#define Sp(p) cout<<setprecision(25)<< fixed<<p<<endl;
int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
int dx2[8] = { 1,1,0,-1,-1,-1,0,1 }, dy2[8] = { 0,1,1,1,0,-1,-1,-1 };
#define fio() cin.tie(0); ios::sync_with_stdio(false);
const ll MOD = 1000000007;
//const ll MOD = 998244353;
// #define mp make_pair
//#define endl '\n'

vector<vector<pii>> G;

signed main() {
  int n;
  cin >> n;
  G.resize(n);
  rep (i, n - 1) {
    int u, v, c;
    cin >> u >> v >> c;
    G[u].emplace_back(v, c);
    G[v].emplace_back(u, c);
  }

  vi a(n), c(16);
  rep (i, n) {
    rep (j, G[i].size()) {
      a[i] ^= G[i][j].second;
    }
    c[a[i]]++;
  }

  int ans = 0;
  ll mask = 0;
  rep (i, 16) {
    if (i == 0) {
      c[i] = 0;
      continue;
    }
    ans += c[i] / 2;
    c[i] %= 2;
    if (c[i]) {
      mask += 1 << i;
    }
  }
  DEBUG_VEC(c);
  vector<vector<bool>> dp(100, vector<bool>(1 << 16, false));
  dp[0][mask] = true;
  rep (i, 100) {
    if (dp[i][0] or dp[i][1]) {
      cout << i + ans << endl;
      return 0;
    }
    rrep (j, 1 << 16) {
      if (not dp[i][j]) continue;
      rep (k1, 16) {
        if (k1 == 0) continue;
        if ((j & (1 << k1)) == 0) continue;
        rep (k2, 16) {
          if (k2 == 0) continue;
          if (k1 == k2) continue;
          if ((j & (1 << k2)) == 0) continue;
          int k3 = k1 ^ k2;
          int nj = j;
          nj -= 1 << k1;
          nj -= 1 << k2;
          nj ^= 1 << k3;
          if (j & (1 << k3)) {
            dp[i + 2][nj] = true;
          }
          else {
            dp[i + 1][nj] = true;
          }
        }
      }
    }
  }
}

Measured memory_bytes: 9472