#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <cstdio>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <cctype>
using namespace std;
int co[100010] = {};
bool bo[100010] = { false };
int ma = -1, mi = -1;
vector<vector<int>>vec(100010);
int d[100010];
int main() {
	int n;
	cin >> n;
	for (int i = 0; i < n - 1; i++) {
		int a, b;
		cin >> a >> b;
		co[a]++;
		co[b]++;
		vec[a].emplace_back(b);
		vec[b].emplace_back(a);
	}
	for (int i = 1; i <= n; i++) {
		if (ma > 2 && co[i] > 2) {
			cout << "No" << endl;
			return 0;
		}
		if (ma < co[i]) {
			ma = co[i];
			mi = i;
		}
	}
	if (ma <= 2) {
		cout << "Yes" << endl;
	}
	else {
		bo[mi] = true;
		d[mi] = 0;
		queue<int> que;
		que.push(mi);
		while (!que.empty()) {
			int now = que.front();
			for (int i = 0; i < vec[now].size(); i++) {
				if (!bo[vec[now][i]]) {
					bo[vec[now][i]] = true;
					d[vec[now][i]] = d[now] + 1;
					que.push(vec[now][i]);
				}
			}
			que.pop();
		}
		set<int> st;
		for (int i = 1; i <= n; i++) {
			if (co[i] == 1) {
				st.insert(d[i]);
			}
		}
		if (st.size() == 1) {
			cout << "Yes" << endl;
		}
		else {
			cout << "No" << endl;
		}
	}
}