#include <bits/stdc++.h>
using namespace std;

const int MAXN = 100001;

vector<int> g[MAXN];

int ans = 0;

int dfs(int x, int p = -1){
	int r = g[x].size() - (x != 1);
	for(int i : g[x]){
		if(i==p)continue;
		r += dfs(i, x);
	}
	ans += min(8, r*2);
	return r;
}

int dfs2(int x, int p = -1){
	int r = (x == 1 ? 2 : (g[x].size()-1)*2);
	for(int i : g[x]){
		if(i==p)continue;
		r += dfs2(i, x);
	}
	ans += min(8*(int)(g[x].size()), r);
	return r;
}

int main() {
	ios::sync_with_stdio(0); cin.tie(0);
	int n; cin >> n;
	for (int i = 0; i < n - 1; i++) {
		int a, b; cin >> a >> b;
		g[a].push_back(b);
		g[b].push_back(a);
	}
	dfs2(1);
	cout<<ans<<"\n";
}