#include<bits/stdc++.h>
using namespace std;

// Shortcut

#define int long long
#define endl '\n'
#define eb emplace_back
#define pb push_back
#define pob pop_back
#define mp make_pair
#define upb upper_bound
#define lwb lower_bound
#define fi first
#define se second
#define For(i, l, r) for (int i = l; i < r; i++)
#define ForE(i, l, r) for (int i = l; i <= r; i++)
#define Ford(i, r, l) for (int i = r; i > l; i--)
#define FordE(i, r, l) for (int i = r; i >= l; i--)
#define Fora(i, a) for (auto i : a)

// I/O & Debug

#define PrintV(a) for (int iiii = 0; iiii < a.size(); iiii++) cout << a[iiii] << ' ';
#define PrintVl(a) for (int iiii = 0; iiii < a.size(); iiii++) cout << a[iiii] << endl;
#define PrintA(a, n) for (int iiii = 0; iiii < n; iiii++) cout << a[iiii] << ' ';
#define PrintAl(a, n) for (int iiii = 0; iiii < n; iiii++) cout << a[iiii] << endl;
#define Ptest(x) return cout << x, 0;
#define gl(s) getline(cin, s);
#define setpre(x) fixed << setprecision(x)
/*
#define debug(args...){ string _sDEB = #args; replace(_sDEB.begin(), _sDEB.end(), ',', ' '); stringstream _ssDEB(_sDEB); istream_iterator<string> _itDEB(_ssDEB); DEB(_itDEB, args); }
void DEB(istream_iterator<string> it) {}
template<typename T, typename... Args>
void DEB(istream_iterator<string> it, T a, Args... args){
    cout << *it << " = " << a << endl;
    DEB(++it, args...);
}
*/

// Functions

//#define isvowel(a) (a == 'a' || a == 'e' || a == 'i' || a == 'o' || a == 'u')
#define bend(a) a.begin(), a.end()
#define rbend(a) a.rbegin(), a.rend()
#define mset(a) memset(a, 0, sizeof(a));
#define mmset(a) memset(a, 0x3f, sizeof(a));
//mt19937 rando(chrono::steady_clock::now().time_since_epoch().count());

// Data Structure

#define pque priority_queue
#define mts multiset
typedef long long ll;
typedef long double ld;
typedef vector <int> vi;
typedef vector <ll> vll;
typedef vector <ld> vld;
typedef vector <string> vs;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
typedef vector <vi > vvi;
typedef vector <vll > vvll;
typedef vector <pii > vpii;
typedef vector <pll > vpll;

const int N = 1e5 + 5, mod = 1e9 + 7, inf = 1e9 + 7;

int n;
int a[N];
vi adj[N];
bool ck = 1;

int dfs(int u, int t){
    if (adj[u].size() == 1){
        return a[u];
    }
    int sum = 0, mx = 0;
    Fora(v, adj[u]){
        if (t == v){
            continue;
        }
        int ans = dfs(v, u);
        if (ans < 0){
            return -1;
        }
        sum += ans;
        mx = max(mx, ans);
    }
    if (sum - a[u] < 0 || min(sum - mx, sum / 2) < sum - a[u] || a[u] * 2 - sum < 0){
        ck = 0;
        return -1;
    }
    return a[u] * 2 - sum;
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    cin >> n;
    ForE(i, 1, n){
        cin >> a[i];
    }
    For(i, 1, n){
        int u, v;
        cin >> u >> v;
        adj[u].pb(v);
        adj[v].pb(u);
    }
    if (n == 2){
        if (a[1] == a[2]) Ptest("YES");
        cout << "NO";
        return 0;
    }
    int st = 1;
    while (adj[st].size() == 1){
        st++;
    }
    if (dfs(st, -1)){
        ck = 0;
    }
    if (ck) Ptest("YES");
    cout << "NO";
}

/*
==================================+
INPUT:                            |
------------------------------    |

------------------------------    |
==================================+
OUTPUT:                           |
------------------------------    |

------------------------------    |
==================================+
*/

Measured memory_bytes: 11904