#include "bits/stdc++.h"
//#include "atcoder/all"
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
//const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n-1); i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define endl "\n"
int N;
vector<int>to[100005];
int dist[100005];
void dfs(int v, int d = 0, int p = -1) {
	dist[v] = d;
	for (int e : to[v]) {
		if (p == e) {
			continue;
		}
		dfs(e, d + 1, v);
	}
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cin >> N;
	rep(i, N - 1) {
		int a, b;
		cin >> a >> b;
		a--;
		b--;
		to[a].push_back(b);
		to[b].push_back(a);
	}
	int count = 0;
	int pos;
	rep(i, N) {
		if (to[i].size() >= 3) {
			count++;
			pos = i;
		}
	}
	if (0 == count) {
		cout << "Yes" << endl;
		return 0;
	}
	if (count > 1) {
		cout << "No" << endl;
		return 0;
	}
	dfs(pos);
	int deep = 1e9;
	bool b = true;
	rep(i, N) {
		if (1 != to[i].size()) {
			continue;
		}
		if (1e9 == deep) {
			deep = dist[i];
		}
		else {
			if (deep != dist[i]) {
				b = false;
			}
		}
	}
	if (b) {
		cout << "Yes" << endl;
	}
	else {
		cout << "No" << endl;
	}
	return 0;
}