//Zory-2020
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
// typedef __int128 ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define FR first
#define SE second
#define MP make_pair
#define PB push_back
#define vc vector
#define db double
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define bin(x) (1ll<<(x))
#define fo(i,l,r) for(int i=(l),I=(r);i<=I;i++)
#define fd(i,r,l) for(int i=(r),I=(l);i>=I;i--)
#define mem(x,val) memset(x,val,sizeof x)
#define Swap(a,b,n) for(int I=0;I<=n;I++) swap(a[I],b[I])
#define PC __builtin_popcountll
#ifdef DEBUG
	#define debug(A,args...) fprintf(stderr,A,##args)
#else
	#define debug(A,args...) 
#endif
namespace mine
{
	ll qread()
	{
		ll ans=0,f=1;char c=getchar();
		while(c<'0' or c>'9') {if(c=='-')f=-1;c=getchar();}
		while('0'<=c and c<='9') ans=ans*10+c-'0',c=getchar();
		return ans*f;
	}
	void write(ll num){if(num<0) putchar('-'),num=-num;if(num>=10) write(num/10);putchar('0'+num%10);}
	void write1(ll num){write(num);putchar(' ');}
	void write2(ll num){write(num);putchar('\n');}
	template<typename T>inline bool chmax(T&a,const T&b){return a<b?a=b,1:0;}
	template<typename T>inline bool chmin(T&a,const T&b){return a>b?a=b,1:0;}
	ll gcd(ll x,ll y){return y?gcd(y,x%y):x;}
	bool IN(ll x,ll l,ll r){return l<=x and x<=r;}
	void GG(){puts("NO");exit(0);}
	
	const db eps=1e-8;
	const int INF=0x3f3f3f3f;
	const int MOD=1e9+7;
	int mm(const int x){return x>=MOD?x-MOD:x;}
	template<typename T> void add(T &x,const int &y){x=(x+y>=MOD?x+y-MOD:x+y);}
	ll qpower(ll x,ll e,int mod=MOD){ll ans=1;while(e){if(e&1)ans=ans*x%mod;x=x*x%mod;e>>=1;}return ans;}
	ll invm(ll x){return qpower(x,MOD-2);}
	const int M=5e6+10;
	ll fac[M],facinv[M],Inv[M];ll C(int n,int m){return n<0 or n<m?0:fac[n]*facinv[m]%MOD*facinv[n-m]%MOD;}
	void PRE()
	{
		fac[0]=1;fo(i,1,M-1) fac[i]=fac[i-1]*i%MOD;
		facinv[M-1]=invm(fac[M-1]);fd(i,M-1,1) facinv[i-1]=facinv[i]*i%MOD;
		Inv[1]=1;fo(i,2,M-1) Inv[i]=(MOD-MOD/i)*Inv[MOD%i]%MOD;
	}
	const int N=1e6+10;
	//------------------FIXED------------------
	vc<int> to[N];pll f[N];ll a[N];
	void solve(int x,int fa)//xһ������Ҷ��
	{
		ll in=0,out=0,up=(sz(to[x])==1)*a[x];//ע��in��out��λ�Ƕ�
		for(auto y:to[x]) if(y!=fa)
		{
			solve(y,x);
			ll com=min(up,f[y].SE);a[x]-=com,out+=com,up-=com,f[y].SE-=com;//up+up=out,a--����Ϊǿ��
			if(f[y].SE){ ll deb=min(out,f[y].SE/2);out+=deb,f[y].SE-=deb*2,a[x]-=deb; }//debug
			up+=f[y].SE;
		}
		a[x]-=up;if(a[x]<0) GG();//��Ϊǿ��
		for(auto y:to[x]) if(y!=fa)//in+in->2out,a-=2
		{
			ll com=min(min(in,f[y].FR),a[x]/2);
			a[x]-=com*2,in=(in-com)+(f[y].FR-com),out+=com*2;
		}
		if(a[x]){ ll com=min(a[x]/2,in);up+=com*2,in-=com, a[x]-=com*2; }
		if(a[x]){ ll com=min(a[x], out);up+=com*2,out-=com,a[x]-=com; }//���Ϊupǿ������
		f[x]={in,up};if(!fa and up) GG();if(a[x]) GG();
	}
	void main()
	{
		int n=qread();fo(i,1,n) a[i]=qread();fo(i,2,n){ int x=qread(),y=qread();to[x].PB(y),to[y].PB(x); }
		if(n==2){ puts(a[1]==a[2]?"YES":"NO");return; }//debug
		int rt=0;fo(i,1,n) if(sz(to[i])>1) rt=i;solve(rt,0);puts("YES");
	}
};//����������
signed main()
{
	#ifdef DEBUG
	//freopen("a.in","r",stdin);
	freopen("z.txt","r",stdin);
	//freopen("a.out","w",stdout);
	#endif
	srand(time(0));
	mine::PRE();//����Ԥ����ģ����
	mine::main();
	debug("\n---------------------Zory---------------------\nTime: %.2lf s",1.0*clock()/CLOCKS_PER_SEC);
}

Measured memory_bytes: 158336