/****** BISMILLAH HIR RAHMANIR RAHIM ******/

#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")


#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
// #include <ext/pb_ds/detail/standard_policies.hpp>

using namespace std;
// using namespace __gnu_pbds;
// using namespace __gnu_cxx;

typedef long long ll;
typedef unsigned int ul;
typedef unsigned long long ull;
typedef vector <int> vi;
typedef map<string,string> mss;
typedef map<int, vector<int> > mvii;
typedef map<int, int> mii;
typedef queue <int> qi;
typedef map <int, vector<string> > mvis;
typedef map <string, vector<int> > mvsi;
typedef vector <string> vs;
typedef pair <int, int> pii;
typedef vector<pair<int,int> > vpii;

// Order Statistic Tree

/* Special functions: 

		find_by_order(k) --> returns iterator to the kth largest element counting from 0
		order_of_key(val) --> returns the number of items in a set that are strictly smaller than our item
*/

// typedef tree<
// int,
// null_type,
// less<int>,
// rb_tree_tag,
// tree_order_statistics_node_update>
// ordered_set;

#define MP make_pair
#define SORT(a) sort (a.begin(), a.end())
#define REVERSE(a) reverse (a.begin(), a.end())
#define ALL(a) a.begin(), a.end()
#define PI acos(-1)
#define ms(x,y) memset (x, y, sizeof (x))
#define INF 2000000000
#define pb push_back
#define MAX 100002
#define debug cout<<"A"<<"\n"
#define prnt(a) cout<<a<<"\n"
#define mod 1000000007LL
#define FOR(i,a,b) for (int i=(a); i<(b); i++)
#define FORr(i,a,b) for (int i=(a); i>=b; i--)
#define itrALL(c,itr) for(__typeof((c).begin()) itr=(c).begin();itr!=(c).end();itr++)
#define lc ((node)<<1)
#define rc ((node)<<1|1)
#define VecPrnt(v) FOR(J,0,v.size()) cout<<v[J]<<" "; cout<<endl
#define endl "\n"
#define PrintPair(x) cout<<x.first<<" "<<x.second<<endl
#define ClearQ(x); while(!x.empty()) x.pop()
#define EPS 1e-9
#define ArrPrint(a,st,en) for(int J=st; J<=en; J++) cout<<a[J]<<" "; cout<<endl;

/* Direction Array */

// int fx[]={1,-1,0,0};
// int fy[]={0,0,1,-1};
// int fx[]={0,0,1,-1,-1,1,-1,1};
// int fy[]={-1,1,0,0,1,1,-1,-1};

template <class T> inline T bigmod(T p,T e,T M)
{
    ll ret = 1;
    for(; e > 0; e >>= 1)
    {
        if(e & 1) ret = (ret * p) % M;
        p = (p * p) % M;
    } return (T)ret;
}

template <class T> inline T gcd(T a,T b){if(b==0)return a;return gcd(b,a%b);}
template <class T> inline T modinverse(T a,T M){return bigmod(a,M-2,M);}
template <class T> inline T lcm(T a,T b) {a=abs(a);b=abs(b); return (a/gcd(a,b))*b;}
template <class T, class X> inline bool getbit(T a, X i) { T t=1; return ((a&(t<<i))>0);}
template <class T, class X> inline T setbit(T a, X i) { T t=1;return (a|(t<<i)); }
template <class T, class X> inline T resetbit(T a, X i) { T t=1;return (a&(~(t<<i)));}

inline ll getnum()
{
    char c = getchar();
    ll num,sign=1;
    for(;c<'0'||c>'9';c=getchar())if(c=='-')sign=-1;
    for(num=0;c>='0'&&c<='9';)
    {
        c-='0';
        num = num*10+c;
        c=getchar();
    }
    return num*sign;
}

inline ll power(ll a, ll b)
{
	ll multiply=1;
	FOR(i,0,b)
	{
		multiply*=a;
	}
	return multiply;
}

/****** END OF HEADER ******/

int n, u, v, k, d[MAX], cnt[20];
vi rest;
int dp[1<<17];

int go(int mask)
{
	// prnt(mask);
	if(mask&1) mask^=1;
	if(mask==0) return 0;
	if(dp[mask]!=-1) return dp[mask];

	int ret=16;

	for(int i=1; i<=16; i++)
	{
		for(int j=1; j<=16; j++)
		{
			if(i==j) continue;
			if((mask&(1<<i)) && (mask&(1<<j)))
			{
				int nxtmask=mask^(1<<i);
				nxtmask^=(1<<j);
				nxtmask^=(1<<(i^j));

				int add=1;

				if(mask&(1<<(i^j)))
				{
					add++;
				}


				ret=min(ret,add+go(nxtmask));
			}
		}
	}

	return dp[mask]=ret;
}

int main()
{
    // ios_base::sync_with_stdio(0);
    // cin.tie(NULL); cout.tie(NULL);
    // freopen("in.txt","r",stdin);

    int test, cases=1;

    scanf("%d", &n);

    FOR(i,0,n-1)
    {
    	scanf("%d%d%d", &u, &v, &k);

    	d[u]^=k;
    	d[v]^=k;
    }

    FOR(i,0,n)
    {
    	if(d[i]) 
    	{
    		// prnt(d[i]);
    		cnt[d[i]]++;
    	}
    }

    int ans=0, mask=0;

    FOR(i,1,17)
    {
    	ans+=cnt[i]/2;
    	if(cnt[i]%2) rest.pb(i), mask|=(1<<i);
    }

    // debug;
    // VecPrnt(rest);
    // prnt(mask);

    // prnt(ans);
    ms(dp,-1);
    prnt(ans+go(mask));

    return 0;
}



Measured memory_bytes: 1152