// Slower C++ solution:
#include "bits/stdc++.h"

using namespace std;

#ifndef LOCAL

#define endl '\n'

#endif



#define fr(i, a, b) for(int i = a; i <= b; i++)

#define rf(i, a, b) for(int i = a; i >= b; i--)

#define pf push_front

#define pb push_back

#define eb emplace_back

#define fi first

#define se second

#define all(x) x.begin(), x.end()

#define rall(x) x.rbegin(), x.rend()

#define sz(x) (int)x.size()

#define lb lower_bound

#define ub upper_bound



typedef long long ll;

typedef long double f80;

typedef pair<int,int> pii;

typedef pair<ll,ll> pll;



int pct(int x) { return __builtin_popcount(x); }

int pct(ll x) { return __builtin_popcountll(x); }

int bt(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

int bt(ll x) { return 63 - __builtin_clzll(x); } // floor(log2(x))

int cdiv(int a, int b) { return a / b + !(a < 0 || a % b == 0); }

ll cdiv(ll a, ll b) { return a / b + !(a < 0 || a % b == 0); }

int nxt_C(int x) { int c = x & -x, r = x + c; return (((r ^ x) >> 2) / c) | r; }

ll nxt_C(ll x) { ll c = x & -x, r = x + c; return (((r ^ x) >> 2) / c) | r; }



vector<int> get_bits(int mask) {

	vector<int> bb;

	while(mask) { int b = bt(mask); bb.pb(b); mask ^= (1 << b); }

	reverse(all(bb));

	return bb;

}



int get_mask(vector<int> v) {

	int mask = 0;

	for(int x : v) { mask ^= (1 << x); }

	return mask;

}



template<typename T>

void uniq(vector<T> &v) { sort(all(v)); v.resize(unique(all(v)) - v.begin()); }



mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());



ll rand(ll l, ll r){

	uniform_int_distribution<ll> uid(l, r);

	return uid(rng);

}



void sc() {}



template <typename Head, typename... Tail>

void sc(Head &H, Tail &... T) { cin >> H; sc(T...); }



#ifdef LOCAL

#define debug(...) cerr << "[L:" << __LINE__ << "][" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)

#else

#define debug(...) 42

#endif



// #ifndef LOCAL

// string to_string(__int128 x) {

// 	string s = "";

// 	bool neg = 0;

// 	if(x < 0) { s += "-"; neg = 1; x = -x; }

// 	if(!x) s += '0';

// 	while(x) {

// 		int rem = x % 10;

// 		s += to_string(rem);

// 		x /= 10;

// 	}

// 	reverse(s.begin() + neg, s.end());

// 	return s;

// }

// #endif



const int mod = 1e9 + 7; // 998244353;



int pwr(int a,ll b) {

	int ans = 1;

	while(b) {

		if(b & 1) ans = (ans * 1LL * a) % mod;

		a = (a * 1LL * a) % mod;

		b >>= 1;

	}

	return ans;

}



/*

	Lookout for overflows!!

	Check array sizes!!

	Clear before test cases!!

	Use the correct modulo!!

	Check for corner cases!!

	Are you forgetting something?!

	Read problem statement carefully!!!

*/



const int N = 1e5 + 5;

vector<int> g[N];

ll a[N], val[N];



void dfs(int u,int p) {

    if(sz(g[u]) == 1) {

        val[u] = a[u];

        return;

    }

    ll s = 2 * a[u];

    ll mx = 0;

    for(int v : g[u]) {

        if(v != p) {

            dfs(v, u);

            s -= val[v];

            mx = max(mx, val[v]);

        }

    }

    val[u] = s;

    mx = max(mx, val[u]);

    if(2 * a[u] < 2 * mx || val[u] < 0) {

        cout << "NO";

        exit(0);

    }

}



void solve() {

	int n;

    sc(n);

    fr(i, 1, n)

        sc(a[i]);

    if(n == 2) {

        cout << ((a[1] == a[2]) ? "YES" : "NO");

        return;

    }

    fr(i, 1, n - 1) {

        int u, v;

        sc(u, v);

        g[u].pb(v);

        g[v].pb(u);

    }

    int r = 0;

    fr(i, 1, n) {

        if(sz(g[i]) > 1) r = i;

    }

    dfs(r, 0);

    if(val[r] > 0) {

        cout << "NO";

        return;

    }

    cout << "YES";

}



int main() {

	ios :: sync_with_stdio(0);

	cin.tie(0);

	cout.tie(0);

	int t = 1;

	// cin >> t;

	for(int tt = 1; tt <= t; tt++) {

		solve();

	}

	return 0;

}

// Faster C++ solution for the same problem (measured speedup: 3.6147264173683045x):
#include <cstdio>

#include <cstdlib>

#include <iostream>



typedef long long LL;



const int MAXN = 1e5;

int n, ecnt, val[MAXN + 5], head[MAXN + 5], d[MAXN + 5];



struct Edge { int to, nxt; } graph[MAXN * 2 + 5];



inline void link ( const int s, const int t ) {

	graph[++ ecnt] = { t, head[s] };

	head[s] = ecnt;

}



inline int DFS ( const int u, const int f ) {

	if ( d[u] == 1 ) return val[u];

	LL sum = 0; int mx = 0;

	for ( int i = head[u], v; i; i = graph[i].nxt ) {

		if ( ( v = graph[i].to ) ^ f ) {

			int up = DFS ( v, u );

			sum += up, mx = std::max ( mx, up );

		}

	}

	if ( sum - val[u] > std::min ( sum >> 1, sum - mx )

		|| 2 * val[u] < sum || sum < val[u] ) puts ( "NO" ), exit ( 0 );

	return 2 * val[u] - sum;

	// a+b=val, 2a+b=sum, a<=min{sum/2,sum-mx}

}



int main () {

	scanf ( "%d", &n );

	for ( int i = 1; i <= n; ++ i ) scanf ( "%d", &val[i] );

	for ( int i = 1, u, v; i < n; ++ i ) {

		scanf ( "%d %d", &u, &v ), ++ d[u], ++ d[v];

		link ( u, v ), link ( v, u );

	}

	if ( n == 2 ) return puts ( val[1] == val[2] ? "YES" : "NO" ), 0;

	for ( int i = 1; i <= n; ++ i )

		if ( d[i] > 1 )

			return puts ( DFS ( i, 0 ) ? "NO" : "YES" ), 0;

	return 0;

}