#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <string>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <stdio.h>
using namespace std;
#define int long long
int MOD = 1000000007;
vector<vector<int> > g;
vector<int> V;
vector<int> sz;
vector<vector<int> > dp;
int INF = (int)1 << 60;
void dfs(int a, int p = -1) {
	sz[a] = V[a] % 2;
	dp[a][0] = 0;
	dp[a][1] = 0;
	dp[a][2] = 0;
	for (int i : g[a]) {
		if (i != p) {
			dfs(i, a);
			sz[a] += sz[i];
			/*if (sz[i] % 2 == 0) {
				dp[a][2] = min(dp[a][2], dp[a][1] + dp[i][1]);
				dp[a][1] = min(dp[a][1], dp[a][0] + dp[i][1]);
			}
			else {*/
			dp[a][2] = min(dp[a][2] + dp[i][0], min(dp[a][1] + dp[i][1], dp[a][0] + dp[i][2]));
			dp[a][1] = min(dp[a][1] + dp[i][0], dp[a][0] + dp[i][1]);
			dp[a][0] = dp[a][0] + dp[i][0];
			//}
		}
	}
	if (V[a] % 2 == 1) {
		dp[a][2] = min(dp[a][2], dp[a][1]);
		dp[a][1] = min(dp[a][1], dp[a][0]);
	}
	if (sz[a] % 2 == 0) {
		dp[a][1]++;
	}
	else {
		dp[a][0]++;
		dp[a][2]++;
	}
	//cerr << a << " " << dp[a][0] << " " << dp[a][1] << " " << dp[a][2] << endl;

}
signed main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	int N;
	cin >> N;
	g.resize(N);
	sz.resize(N, 0);
	V.resize(N, 0);
	dp.resize(N, vector<int>(3, 0));
	int res = 0;
	int a, b;
	for (int i = 0; i < N - 1; i++) {
		cin >> a >> b;
		a--; b--;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	for (int i = 0; i < N - 1; i++) {
		cin >> a >> b;
		a--; b--;
		V[a]++;
		V[b]++;
	}
	dfs(0);
	cout << dp[0][2] + N - 1 << endl;

}