#include <cstdio>
#include <cctype>
#include <algorithm>

const int N = 1e5 + 7;

inline int read() {
	char ch = getchar(); int r = 0, w = 1;
	while(!isdigit(ch)) {if(ch == '-') w = -1; ch = getchar();}
	while(isdigit(ch)) {r = r * 10 + ch - '0', ch = getchar();}
	return r * w;
}

int n;
int tot, w[N], cnt[32], p[20], dp[1 << 16], ans;

inline int calc(int x) {
	int now = 0, res = 0, sz = 0;
	while(x) {
		if(x & 1) res ^= p[now], sz++;
		x >>= 1;
		now++;
	}
	return res ? sz : sz - 1;
}

int main() {
	n = read();
	for(register int i = 1; i < n; i++) {
		int x = read() + 1, y = read() + 1, z = read();
		w[x] ^= z, w[y] ^= z;
	}
	for(register int i = 1; i <= n; i++)
		cnt[w[i]]++;
	for(register int i = 1; i <= 31; i++) {
		ans += cnt[i] / 2;
		if(cnt[i] & 1)
			p[tot++] = i;
	}
	for(register int S = 1; S < 1 << tot; S++) {
		dp[S] = calc(S);
		for(register int T = S; T; T = (T - 1) & S) {
			dp[S] = std::min(dp[S], dp[T] + dp[S ^ T]);
		}
	}
	if(tot > 1) printf("%d\n", ans + dp[(1 << (tot - 1)) - 1]);
	else printf("%d\n", ans);
	return 0;
}