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#pragma GCC target("sse4,tune=native")
#pragma GCC optimize("O3","unroll-loops")
#include <iostream>
#include <complex>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <numeric>
#include <cstring>
#include <ctime>
#include <cstdlib>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <cmath>
#include <bitset>
#include <cassert>
#include <queue>
#include <stack>
#include <deque>
    
     
using namespace std;
template<typename T1, typename T2>inline void chkmin(T1 &x, T2 y) { if (x > y) x = y; }
template<typename T1, typename T2>inline void chkmax(T1 &x, T2 y) { if (x < y) x = y; } 
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const pair<T, U> &_p) { _out << _p.first << ' ' << _p.second; return _out; }
template<typename T, typename U> inline istream &operator>> (istream &_in, pair<T, U> &_p) { _in >> _p.first >> _p.second; return _in; }
template<typename T> inline ostream &operator<< (ostream &_out, const vector<T> &_v) { if (_v.empty()) { return _out; } _out << _v.front(); for (auto _it = ++_v.begin(); _it != _v.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline istream &operator>> (istream &_in, vector<T> &_v) { for (auto &_i : _v) { _in >> _i; } return _in; }
template<typename T> inline ostream &operator<< (ostream &_out, const set<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const multiset<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const unordered_set<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const unordered_multiset<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const map<T, U> &_m) { if (_m.empty()) { return _out; } _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')'; for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) { _out << ", (" << _it->first << ": " << _it->second << ')'; } return _out; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const unordered_map<T, U> &_m) { if (_m.empty()) { return _out; } _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')'; for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) { _out << ", (" << _it->first << ": " << _it->second << ')'; } return _out; }
#define sz(c) (int)(c).size()
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define left left228
#define right right228
#define next next228
#define rank rank228
#define prev prev228
#define y1 y1228                                                         
#define read(FILENAME) freopen((FILENAME + ".in").c_str(), "r", stdin)
#define write(FILENAME) freopen((FILENAME + ".out").c_str(), "w", stdout)
#define files(FILENAME) read(FILENAME), write(FILENAME)
#define pb push_back
const string FILENAME = "input";
const int MAXN = 100228;
//13:35
//15:35
int n;
vector<int> g[MAXN];
int c[MAXN];


long long dfs(int u, int pr = -1) {
	long long sum = 0;
	int cnts = 0;
	long long maxson = 0;
	for (auto h: g[u]) {
		if (h != pr) {
			cnts++;
			long long k = dfs(h, u);
			sum += k;
			chkmax(maxson, k);
		}
	}
	if (cnts == 0) {
		return c[u];
	}
	if (sum < c[u]) {
		cout << "NO\n";
		exit(0);
	}
	if (sum > c[u]) {
		// int t;
		// t * 2 + rest == sum;
		// t + rest == c[u]
		// t = sum - c[u]
		long long t = sum - c[u];
		if (maxson * 2 >= sum) {
			if (t > sum - maxson) {
				cout << "NO\n";
				exit(0);
			}
		} 
		sum -= t * 2;
		assert(t + sum == c[u]);
		if (sum < 0) {
			cout << "NO\n";
			exit(0);
		}
	}
	return sum;
}


int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	//read(FILENAME);
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> c[i];
	}
	for (int i = 0; i < n - 1; i++) {
		int a, b;
		cin >> a >> b;
		a--, b--;
		g[a].pb(b);
		g[b].pb(a);
	}
	if (n == 2) {
		if (c[0] != c[1]) {
			cout << "NO\n";
			return 0;
		}
		cout << "YES\n";
		return 0;
	}
	int root = 0;
	for (int i = 0; i < n; i++) {
		if (sz(g[i]) >= 2) {
			root = i;
		}
	}
	if (dfs(root)) {
		cout << "NO\n";
		return 0;
	}
	cout << "YES\n";
	return 0;			
}


Measured memory_bytes: 14720