#include <iostream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstdlib>
#include <cassert>
#include <vector>
#include <list>
#include <stack>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <bitset>
#include <string>
#include <algorithm>
#include <utility>
#include <complex>
#define rep(x, s, t) for(llint (x) = (s); (x) <= (t); (x)++)
#define reps(x, s) for(llint (x) = 0; (x) < (llint)(s).size(); (x)++)
#define chmin(x, y) (x) = min((x), (y))
#define chmax(x, y) (x) = max((x), (y))
#define sz(x) ((ll)(x).size())
#define ceil(x, y) (((x)+(y)-1) / (y))
#define all(x) (x).begin(),(x).end()
#define outl(...) dump_func(__VA_ARGS__)
#define inf 1e18

using namespace std;

typedef long long llint;
typedef long long ll;
typedef pair<ll, ll> P;
bool exceed(ll x, ll y, ll m){return x >= m / y + 1;}

struct edge{
	ll to, cost;
	edge(){}
	edge(ll a, ll b){
		to = a, cost = b;
	}
};

template<typename T>
ostream& operator << (ostream& os, vector<T>& vec) {
	for(int i = 0; i<vec.size(); i++) {
		os << vec[i] << (i + 1 == vec.size() ? "" : " ");
	}
	return os;
}
template<typename T, typename U>
ostream& operator << (ostream& os, pair<T, U>& pair_var) {
	os << "(" << pair_var.first << ", " << pair_var.second << ")";
	return os;
}
template<typename T, typename U>
ostream& operator << (ostream& os, map<T, U>& map_var) {
	for(typename map<T, U>::iterator itr = map_var.begin(); itr != map_var.end(); itr++) {
		os << "(" << itr->first << ", " << itr->second << ")";
		itr++;
		if(itr != map_var.end()) os << ",";
		itr--;
	}
	return os;
}
template<typename T>
ostream& operator << (ostream& os, set<T>& set_var) {
	for(typename set<T>::iterator itr = set_var.begin(); itr != set_var.end(); itr++) {
		os << *itr;
		++itr;
		if(itr != set_var.end()) os << " ";
		itr--;
	}
	return os;
}
void dump_func() {cout << endl;}
template <class Head, class... Tail>
void dump_func(Head &&head, Tail &&... tail) {
    cout << head;
    if(sizeof...(Tail) > 0) cout << " ";
    dump_func(std::move(tail)...);
}


llint dtmp[100005];
void distdfs(vector<llint> G[], int v, int p, llint d)
{
	dtmp[v] = d;
	for(int i = 0; i < G[v].size(); i++){
		llint u = G[v][i], c = 1; //
		if(u == p) continue;
		distdfs(G, u, v, d+c);
	}
}

llint getDiameter(vector<llint> G[], llint n, llint &u, llint &v)
{
	distdfs(G, 1, -1, 0);
	llint max_val = -1, max_v;
	for(int i = 1; i <= n; i++){
		if(max_val < dtmp[i]){
			max_val = dtmp[i];
			max_v = i;
		}
	}
	u = max_v;
	
	distdfs(G, u, -1, 0);
	max_val = -1;
	for(int i = 1; i <= n; i++){
		if(max_val < dtmp[i]){
			max_val = dtmp[i];
			max_v = i;
		}
	}
	v = max_v;
	
	return max_val;
}

ll n;
vector<ll> G[100005];

vector<ll> vec;
bool dfs(int v, int p, int t)
{
	if(v == t){
		vec.push_back(v);
		return true;
	}
	for(auto u : G[v]){
		if(u == p) continue;
		if(dfs(u, v, t)){
			vec.push_back(v);
			return true;
		}
	}
	return false;
}

set<ll> S;
void dfs2(int v, int p, int d)
{
	if(sz(G[v]) == 1) S.insert(d);
	for(auto u : G[v]){
		if(u == p) continue;
		dfs2(u, v, d+1);
	}
}

int main(void)
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	
	cin >> n;
	ll u, v;
	rep(i, 1, n-1){
		cin >> u >> v;
		G[u].push_back(v);
		G[v].push_back(u);
	}
	
	ll cnt = 0;
	rep(i, 1, n) if(sz(G[i]) == 1) cnt++;
	if(cnt == 2){
		outl("Yes");
		return 0;
	}
	
	ll d = getDiameter(G, n, u, v);
	dfs(u, -1, v);
	
	if(d % 2){
		outl("No");
		return 0;
	}
	
	ll r = vec[d/2];
	dfs2(r, -1, 0);
	
	rep(i, 1, n){
		if(i == r) continue;
		if(sz(G[i]) > 2){
			outl("No");
			return 0;
		}
	}
	
	if(sz(S) == 1) outl("Yes");
	else outl("No");
	
	return 0;
}