// Original C++ solution (slower):


#include<stdio.h>

#include<math.h>

#include<string.h>

#include<iostream>

#include<algorithm>

#include<vector>

#include<utility>

#include<stack>

#include<queue>

#include<map>

#include<set>



#define fi first

#define se second

#define long long long



using namespace std;



vector<int> vec[100003], chi[100003];

bool visited[100003];

long A[100003];

int root = 0;



void dfs(int u)

{

    visited[u] = 1;

    long sum = 0;

    long mx = 0;

    for(int v : vec[u])

    {

        if(visited[v]) continue;

        chi[u].push_back(v);

        dfs(v);

        sum += A[v];

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

    }

//    printf("%d %d %d\n", u, A[u], sum);

    

    if(chi[u].size() == 0)

    {

        return;

    }

    

    if(sum < A[u])

    {

        printf("NO\n");

        exit(0);

    }

    if(sum > 2*A[u])

    {

        printf("NO\n");

        exit(0);

    }

    

    long dif = sum-A[u];

     A[u] -= dif;

    if(sum-mx < dif)

    {

        printf("NO\n");

        exit(0);

    }

    

}



int main()

{

//        freopen("input.in", "r", stdin);

    int n;

    scanf("%d", &n);

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

        scanf("%lld", &A[i]);

    

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

    {

        int u, v;

        scanf("%d %d", &u, &v);

        vec[u].push_back(v);

        vec[v].push_back(u);

    }

    

    if(n == 2)

    {

        if(A[1] == A[2]) printf("YES\n");

        else printf("NO\n");

        return 0;

    }

    

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

    {

        if(root == 0 && vec[i].size() != 1)

            root = i;

    }

    

    dfs(root);

    

//    printf("ROOT : %d %lld\n", root, A[root]);

    

    if(A[root]) printf("NO\n");

    else printf("YES\n");

}


// Optimized solution to the same problem (faster):
#include <bits/stdc++.h>

using namespace std;



#define Int register int

#define MAXN 100005



template <typename T> inline void read (T &t){t = 0;char c = getchar();int f = 1;while (c < '0' || c > '9'){if (c == '-') f = -f;c = getchar();}while (c >= '0' && c <= '9'){t = (t << 3) + (t << 1) + c - '0';c = getchar();} t *= f;}

template <typename T,typename ... Args> inline void read (T &t,Args&... args){read (t);read (args...);}

template <typename T> inline void write (T x){if (x < 0){x = -x;putchar ('-');}if (x > 9) write (x / 10);putchar (x % 10 + '0');}



int n,a[MAXN],f[MAXN],deg[MAXN];

struct edge{

	int v,nxt;

}e[MAXN << 1];

int top = 1,head[MAXN];

void Add_Edge (int u,int v){

	e[++ top] = edge {v,head[u]};head[u] = top;

	e[++ top] = edge {u,head[v]};head[v] = top;

}



bool dfs (int u,int fa){

	if (deg[u] == 1) return f[u] = a[u],1;

	f[u] = 2 * a[u];int Maxn = 0;

	for (Int i = head[u];i;i = e[i].nxt){

		int v = e[i].v;

		if (v == fa) continue;

		if (!dfs (v,u)) return 0;

		f[u] -= f[v],Maxn = max (Maxn,f[v]);

	}

	if (0 <= f[u] && f[u] <= a[u] && Maxn <= a[u]) return 1;

	else return 0;

}



signed main(){

	read (n);

	for (Int i = 1;i <= n;++ i) read (a[i]);

	for (Int i = 2,u,v;i <= n;++ i) read (u,v),Add_Edge (u,v),deg[u] ++,deg[v] ++;

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

	for (Int i = 1;i <= n;++ i) if (deg[i] > 1) return puts (dfs (i,0) && !f[i] ? "YES" : "NO"),0;

	return 0;

} 

// Fastest known solution for this problem: