#include <fstream>
#include <vector>
using namespace std;
ifstream f("asmax.in");
ofstream g("asmax.out");
vector<int> graph[16010];
int n, cost[16010], nod1, nod2, smax=-2000000000, sum, d[16010];
bool mark[16010];
void dfs(int vert)
{
    mark[vert]=1;
    d[vert]=cost[vert];
    for (int i=0; i<graph[vert].size(); i++) {
        if (!mark[graph[vert][i]])
            dfs(graph[vert][i]);
        if (cost[graph[vert][i]] > 0)
            d[vert]+=cost[graph[vert][i]];
    }
}
int main()
{
    f>>n;
    for (int i=1; i<=n; i++)
        f>>cost[i];
    for (int i=1; i<n; i++) {
        f>>nod1>>nod2;
        graph[nod1].push_back(nod2);
        graph[nod2].push_back(nod1);
    }
    for (int i=1; i<=n; i++) {
        if (!mark[i]) {
            sum=0;
            dfs(i);
        }
    }
    for (int i=1; i<=n; i++) {
        if (d[i]>smax)
            smax=d[i];
    }
    g<<smax;
    return 0;
}