//It is made by M_sea
#include <algorithm>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <cmath>
#define re register
using namespace std;

inline int read() {
	int X=0,w=1; char c=getchar();
	while (c<'0'||c>'9') { if (c=='-') w=-1; c=getchar(); }
	while (c>='0'&&c<='9') X=X*10+c-'0',c=getchar();
	return X*w;
}

const int N=200000+10;

int w[N],cnt[20],f[1<<15],sxor[1<<15];

int main() {
	int n=read();
	for (re int i=1;i<n;++i) {
		int u=read()+1,v=read()+1,val=read();
		w[u]^=val,w[v]^=val;
	}
	for (re int i=1;i<=n;++i) ++cnt[w[i]];
	int ans=0,s=0;
	for (re int i=1;i<=15;++i) ans+=cnt[i]/2,s|=(cnt[i]&1)<<(i-1);
	for (re int i=1;i<(1<<15);++i) f[i]=f[i>>1]+(i&1);
	for (re int i=1;i<(1<<15);++i) --f[i];
	for (re int i=1;i<(1<<15);++i)
		for (re int j=1;j<=15;++j)
			if (i&(1<<(j-1))) sxor[i]^=j;
	for (re int i=1;i<(1<<15);++i) {
		if (sxor[i]) continue;
		for (re int j=i&(i-1);j;j=(j-1)&i)
			if (!sxor[j]) f[i]=min(f[i],f[j]+f[i^j]);
	}
	printf("%d\n",ans+f[s]);
	return 0;
}
