#include<stdio.h>
#include<vector>

using namespace std;;
const int N_MAX = 16010;
int n;
vector<int> v[N_MAX];
int a[N_MAX], costg[N_MAX],sol=-1000;
bool g[N_MAX];

void dfs(int varf)
{
    int i, cost = 0;
    g[varf] = 1;
    for(i=0;i<v[varf].size();++i)
    {
        if(!g[v[varf][i]])
        {
            dfs(v[varf][i]);
            if(costg[v[varf][i]]>0)
                cost+=costg[v[varf][i]];
        }
    }
    costg[varf] = a[varf]+cost;
    if(sol < costg[varf])
        sol = costg[varf];
}
int main()
{
	int i,x,y;
	freopen("asmax.in","r",stdin);
	freopen("asmax.out","w",stdout);
	scanf("%d",&n);
	for(i=1;i<=n;i++)
	{
		scanf("%d",&a[i]);
	}
	for(i=1;i<=n;i++)
	{
		scanf("%d%d",&x,&y);
		v[x].push_back(y);
		v[y].push_back(x);
	}
	dfs(1);
	printf("%d", sol);
	return 0;
}