#pragma GCC optimize "O3"
#include<bits/stdc++.h>
using namespace std;
using LL=long long;
#define FOR(i,l,r) for(int i=(l);i<=(r);++i)
#define REP(i,n) FOR(i,0,(n)-1)
#define ssize(x) int(x.size())
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(x...) cerr<<"["#x"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(x)
#else
#define debug(...) {}
#endif

int main() {
	cin.tie(0)->sync_with_stdio(0);

	int n;
	cin >> n;
	vector<set<int>> graph(n);
	vector<int> cnt(n, 1);
	REP(i, n - 1) {
		int a, b;
		cin >> a >> b;
		--a, --b;
		graph[a].emplace(b);
		graph[b].emplace(a);
	}
	using P = pair<int, int>;
	priority_queue<P, vector<P>, greater<>> q;
	REP(i, n) {
		if (ssize(graph[i]) == 1)
			q.emplace(1, i);
	}
	int iters = 0;
	while (iters < n - 1 and ssize(q)) {
		auto [_, v] = q.top();
		debug(_, v);
		q.pop();
		auto x = *graph[v].begin();
		if (cnt[x] < cnt[v]) {
			break;
		}
		++iters;
		cnt[x] += cnt[v];
		graph[x].erase(v);
		if (ssize(graph[x]) == 1)
			q.emplace(cnt[x], x);
	}
	if (iters == n - 1) {
		cout << "YES\n";
	}
	else {
		cout << "NO\n";
	}
}