#ifndef __clang__
#pragma GCC optimize "-O3"
#pragma GCC target "tune=native"
#endif
#ifdef ONLINE_JUDGE
#define NDEBUG 1
#endif
#include <stdio.h>
#include <bits/stdc++.h>

#define FOR(i, n)     for(lli i = 0; i < (lli)(n); ++i)
#define FORU(i, j, k) for(lli i = (j); i <= (lli)(k); ++i)
#define FORD(i, j, k) for(lli i = (j); i >= (lli)(k); --i)

#define SQ(x) ((x)*(x))

#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define eb emplace_back

using namespace std;

template<typename... As>
struct tpl : public std::tuple<As...> {
  using std::tuple<As...>::tuple;
  tpl(){}
  tpl(std::tuple<As...> const& b) { std::tuple<As...>::operator=(b); }

  template<typename T = tuple<As...> >
  typename tuple_element<0, T>::type const&
  x() const { return get<0>(*this); }
  template<typename T = tuple<As...> >
  typename tuple_element<0, T>::type&
  x() { return get<0>(*this); }

  template<typename T = tuple<As...> >
  typename tuple_element<1, T>::type const&
  y() const { return get<1>(*this); }
  template<typename T = tuple<As...> >
  typename tuple_element<1, T>::type&
  y() { return get<1>(*this); }

  template<typename T = tuple<As...> >
  typename tuple_element<2, T>::type const&
  z() const { return get<2>(*this); }
  template<typename T = tuple<As...> >
  typename tuple_element<2, T>::type&
  z() { return get<2>(*this); }

  template<typename T = tuple<As...> >
  typename tuple_element<3, T>::type const&
  w() const { return get<3>(*this); }
  template<typename T = tuple<As...> >
  typename tuple_element<3, T>::type&
  w() { return get<3>(*this); }
};

using lli   = long long int;
using llu   = long long unsigned;

using pii   = tpl<lli, lli>;
using piii  = tpl<lli, lli, lli>;
using piiii = tpl<lli, lli, lli, lli>;
using vi    = vector<lli>;
using vii   = vector<pii>;
using viii  = vector<piii>;
using vvi   = vector<vi>;
using vvii  = vector<vii>;
using vviii = vector<viii>;

template<class T>
using min_queue = priority_queue<T, vector<T>, greater<T> >;
template<class T>
using max_queue = priority_queue<T>;

template<size_t... I>
struct my_index_sequence {
  using type = my_index_sequence;
  static constexpr array<size_t, sizeof...(I)> value = { {I...} };
};

namespace my_index_sequence_detail {
  template<typename I, typename J> struct concat;
  template<size_t... I, size_t... J>
  struct concat<my_index_sequence<I...>, my_index_sequence<J...> > :
    my_index_sequence<I..., (sizeof...(I)+J)...> { };
  template<size_t N> struct make_index_sequence :
    concat<typename make_index_sequence<N/2>::type, typename make_index_sequence<N-N/2>::type>::type { };
  template <> struct make_index_sequence<0> : my_index_sequence<>{};
  template <> struct make_index_sequence<1> : my_index_sequence<0>{};
}

template<class... A>
using my_index_sequence_for = typename my_index_sequence_detail::make_index_sequence<sizeof...(A)>::type;

template<class T, size_t... I>
void print_tuple(ostream& s, T const& a, my_index_sequence<I...>){
  using swallow = int[];
  (void)swallow{0, (void(s << (I == 0? "" : ", ") << get<I>(a)), 0)...};
}

template<class T>
ostream& print_collection(ostream& s, T const& a);
template<class... A>
ostream& operator<<(ostream& s, tpl<A...> const& a);
template<class... A>
ostream& operator<<(ostream& s, tuple<A...> const& a);
template<class A, class B>
ostream& operator<<(ostream& s, pair<A, B> const& a);

template<class T, size_t I>
ostream& operator<<(ostream& s, array<T, I> const& a) { return print_collection(s, a); }
template<class T>
ostream& operator<<(ostream& s, vector<T> const& a) { return print_collection(s, a); }
template<class T, class U>
ostream& operator<<(ostream& s, multimap<T, U> const& a) { return print_collection(s, a); }
template<class T>
ostream& operator<<(ostream& s, multiset<T> const& a) { return print_collection(s, a); }
template<class T, class U>
ostream& operator<<(ostream& s, map<T, U> const& a) { return print_collection(s, a); }
template<class T>
ostream& operator<<(ostream& s, set<T> const& a) { return print_collection(s, a); }

template<class T>
ostream& print_collection(ostream& s, T const& a){
  s << '[';
  for(auto it = begin(a); it != end(a); ++it){
    s << *it;
    if(it != prev(end(a))) s << " ";
  }
  return s << ']';
}

template<class... A>
ostream& operator<<(ostream& s, tpl<A...> const& a){
  s << '(';
  print_tuple(s, a, my_index_sequence_for<A...>{});
  return s << ')';
}

template<class... A>
ostream& operator<<(ostream& s, tuple<A...> const& a){
  s << '(';
  print_tuple(s, a, my_index_sequence_for<A...>{});
  return s << ')';
}

template<class A, class B>
ostream& operator<<(ostream& s, pair<A, B> const& a){
  return s << "(" << get<0>(a) << ", " << get<1>(a) << ")";
}

//------------------------------------------------------------------------------

// const int na = 1<<11;
// int A[na];

lli f(lli bs) {
  // vector<unordered_map<int,int>> G(1<<16);
  // FOR(m,1<<16) FOR(i,16) if(i&&(m&(1<<i))) FOR(j,16) if(i<j&&j&&(m&(1<<j))) FOR(l,16) if(l) {
  //       lli co = 1;
  //       lli i2 = i^l;
  //       lli j2 = j^l;
  //       lli m2 = m^(1<<i)^(1<<j);
  //       if(i2) {
  //         if(m2&(1<<i2)) co++;
  //         m2^=(1<<i2);
  //       }
  //       if(j2){
  //         if(m2&(1<<j2)) co++;
  //         m2^=(1<<j2);
  //       }
  //       if(G[m2].count(m)) { G[m2][m] = min<int>(G[m2][m],co); }
  //       else G[m2][m] = co;
  //     }
  min_queue<pii> Q; vi D(1<<16,1ll<<60);
  Q.push(mt(0,0)); D[0] = 0;
  while(!Q.empty()) {
    lli d,m; tie(d,m) = Q.top(); Q.pop();
    if(D[m] != d) continue;
    if(m == bs) return d;
    FOR(i,16) if(i) FOR(j,16) if(i<j&&j) FOR(l,16) if(l && (l!=(i^j))) {
          int i2 = i^l;
          int j2 = j^l;
          int m2 = m;
          int co = 1;
          assert(i2!=j2);
          if(i2) {m2 ^= (1<<i2);
            if(m2&(1<<i2)) co++;
          }
          if(j2) {m2 ^= (1<<j2);
            if(m2&(1<<j2)) co++;
          }
          m2 ^= (1<<i);
          m2 ^= (1<<j);
          if(d+co < D[m2]) { D[m2] = d+co; Q.push(mt(D[m2],m2)); }
        }
    // for(auto e : G[m]) {
    //   lli dd,m2; tie(m2,dd) = e;
    //   dd += d;
    //   if(dd < D[m2]) { D[m2] = dd; Q.push(mt(dd,m2)); }
    // }
  }
  assert(0);
}

int main(){
  ios::sync_with_stdio(0); cin.tie(0);
  lli n; cin>>n;
  vi D(n);
  FOR(i,n-1) {
    lli u,v,e; cin>>u>>v>>e;
    D[u] ^= e; D[v] ^= e;
  }
  vi C(16); FOR(i,n) C[D[i]]++;
  lli ans=0;
  lli bs = 0;
  FOR(i,16) if(i) {
    ans += C[i]/2;
    C[i] %= 2;
    if(C[i]) bs |= (1<<i);
  }
  cout << ans+f(bs) << endl;

  return 0;
}


Measured memory_bytes: 1664