#include <fstream.h>
#define N 16001
using namespace std;
ifstream fin("asmax.in");
ofstream fout("asmax.out");
struct nod {int info;nod *urm;};
int n,tati[N],radacina;
nod *fii[N],*q,*p;
long long v[N];
void citire()
{
fin>>n;
int i;
for(i=1;i<=n;i++)
	{
	fin>>v[i];
	tati[i]=0;
	}
int a,b;
for(i=1;i<n;i++)
	{
	fin>>a>>b;    
	q=new nod;
	q->info=b;
	q->urm=fii[a];
	fii[a]=q;
	tati[b]=a;
	}
for(i=1;i<=n;i++)
if(tati[i]==0)
	{
	radacina=i;
	break;
	}
}
int max(int a,int b)
{
if(a>b) return a;
return b;
}

void progdin(int nod)
{
p=fii[nod];
int i;
	while(p)
	{
	progdin(p->info);
	p=p->urm;
	}
p=fii[nod];
while(p)
{
v[nod]=max(v[nod],v[nod]+v[p->info]);
p=p->urm;
}
}
int main()
{
int max,i;
citire();
progdin(radacina);
max=v[1];
for(i=2;i<=n;i++)
if (max<=v[i])
max=v[i];
fout<<max<<'\n';
return 0;
fin.close();
fout.close();
}