//{{{
#include <bits/stdc++.h>
using namespace std;
//types
typedef long long ll;
typedef pair<int,int> pii;
//input
bool SR(int &_x){return scanf("%d",&_x)==1;}bool SR(ll &_x){return scanf("%lld",&_x)==1;}
bool SR(double &_x){return scanf("%lf",&_x)==1;}bool SR(char *_s){return scanf("%s",_s)==1;}
bool RI(){return true;}
template<typename I,typename... T>bool RI(I &_x,T&... _tail){return SR(_x) && RI(_tail...);}
//output
void SP(const int _x){printf("%d",_x);}void SP(const ll _x){printf("%lld",_x);}
void SP(const double _x){printf("%.16lf",_x);}void SP(const char *s){printf("%s",s);}
void PL(){puts("");}
template<typename I,typename... T>void PL(const I _x,const T... _tail)
{SP(_x);if(sizeof...(_tail)) putchar(' ');PL(_tail...);}
//macro
#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()
#define REP(i,n) for(int i=0;i<int(n);i++)
#define REP1(i,a,b) for(int i=(a);i<=int(b);i++)
#define PER1(i,a,b) for(int i=(a);i>=int(b);i--)
#define pb push_back
#define mkp make_pair
#define F first
#define S second
//debug
#ifdef darry140
template<typename A,typename B>
ostream& operator <<(ostream&_s, const pair<A,B> &_p){return _s<<"("<<_p.F<<","<<_p.S<<")";}
template<typename It>
ostream& _OUTC(ostream &_s,It _b,It _e)//container
{
    _s<<"{";
    for(auto _it=_b;_it!=_e;_it++) _s<<(_it==_b?"":" ")<<*_it;
    _s<<"}";
    return _s;
}
template<typename A,typename B>
ostream& operator <<(ostream&_s, const map<A,B> &_c){return _OUTC(_s,ALL(_c));}
template<typename T>
ostream& operator <<(ostream&_s, const set<T> &_c){return _OUTC(_s,ALL(_c));}
template<typename T>
ostream& operator <<(ostream&_s, const vector<T> &_c){return _OUTC(_s,ALL(_c));}
template<typename I>
void _DOING(const char *_s,I&& _x){cerr<<_s<<"="<<_x<<endl;}//without ','
template<typename I,typename... T>
void _DOING(const char *_s,I&& _x,T&&... _tail)//with ','
{
    int _c=0;
    static const char _bra[]="({[";
    static const char _ket[]=")}]";
    while(*_s!=',' || _c!=0)//eg. mkp(a,b)
    {
        if(strchr(_bra,*_s)) _c++;
        if(strchr(_ket,*_s)) _c--;
        cerr<<*_s++;
    }
    cerr<<"="<<_x<<", ";
    _DOING(_s+1,_tail...);
}
#define debug(...) do{\
    fprintf(stderr,"%s:%d - ",__PRETTY_FUNCTION__,__LINE__);\
    _DOING(#__VA_ARGS__,__VA_ARGS__);\
}while(0)
#else
#define debug(...)
#endif
//}}}
const int maxn=1e5+5;
int n;
vector<int> edge[maxn];
ll c[maxn];
void read()
{
    RI(n);
    REP1(i,1,n) RI(c[i]);
    REP(i,n-1)
    {
        int a,b;RI(a,b);
        edge[a].pb(b);
        edge[b].pb(a);
    }
}
int root;
void build()
{
    if(n==2)
    {
        PL(c[1]==c[2]?"YES":"NO");
        exit(0);
    }
    REP1(i,1,n) if(SZ(edge[i])!=1)
        root=i;
}
ll dfs(int u,int p)
{
    if(SZ(edge[u])==1) return c[u];
    vector<ll> sub;
    for(int v:edge[u]) if(v!=p)
        sub.pb(dfs(v,u));
    ll sum=accumulate(ALL(sub),0LL);
    ll k=sum-c[u];//op
    debug(root,u,sum,k);
    if(k<0 || c[u]-k<0){PL("NO");exit(0);}
    sort(ALL(sub));
    if((sub.back()-(c[u]-k))>(sum-sub.back())){PL("NO");exit(0);}
    return c[u]-k;
}
void sol()
{
    if(dfs(root,0)!=0) PL("NO");
    else PL("YES");
}
int main()
{
    read();
    build();
    sol();
    return 0;
}




































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Measured memory_bytes: 16512