#include <bits/stdc++.h>

//#pragma GCC optimize("O3")
//#define int long long

using namespace std;

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> vi;

void dfs(int u, int p, vector<vector<int>> &g, vector<int> &s, vector<int> &roots, int n){
	s[u] = 1;
	for(int v : g[u]) if(v != p){
		dfs(v, u, g, s, roots, n);
		s[u] += s[v];
	}
	int canroot = 1;
	for(int v : g[u]) if(v != p){
		if(s[v] > n-s[v]) canroot = 0;
	}
	if(n-s[u] > s[u]) canroot = 0;
	if(canroot) roots.push_back(u);
}

int solve(int u, int p, vector<vector<int>> &g, int &poss){
	vector<int> kids;
	for(int v : g[u]) if(v != p){
		kids.push_back(solve(v, u, g, poss));
		if(!poss) return 0;
	}
	sort(begin(kids), end(kids));
	int sz = 1;
	for(int i = 0; i < sz(kids); i++){
		if(kids[i] > sz){
			poss = 0;
			return 0;
		}
		sz += kids[i];
	}
	return sz;
}

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(0);
	int n;
	cin >> n;
	vector<vector<int>> g(n);
	for(int i = 1, u, v; i < n; i++){
		cin >> u >> v;
		u--, v--;
		g[u].push_back(v);
		g[v].push_back(u);
	}
	vector<int> s(n), roots;
	dfs(0, 0, g, s, roots, n);
	for(int r : roots){
		int poss = 1;
		solve(r, r, g, poss);
		if(poss){
			cout << "YES\n";
			return 0;
		}
	}
	cout << "NO\n";
}