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

#define MAX 16001

using namespace std;

int sol[MAX];
int vizitat[MAX];
int val[MAX];
vector <int> v[MAX];
int n, x, y, i;

void dfs (int nod)
{
    int i;
    vizitat[nod] = 1;
    for ( i = 0; i < v[nod].size(); i ++ )
    {
        if( !vizitat[ v[nod][i] ] )
        {
            dfs(v[nod][i]);
            if ( sol[ v[nod][i] ] > 0 )
                sol[nod] += sol[ v[nod][i] ];
        }
    }
}

int main()
{
    FILE *fis = fopen("asmax.in", "r");
    fscanf(fis, "%d", &n);

    for ( i = 1; i <= n; i ++ )
        fscanf(fis, "%d", &sol[i]);

    for ( i = 1; i < n; i++ )
    {
        fscanf(fis, "%d %d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }

    dfs(1);

    sort(sol+1,sol+n+1);

    fclose(fis);
    FILE *fis2 = fopen ("asmax.out", "w");

    fprintf(fis2, "%d\n", sol[n]);
    fclose(fis2);

    return 0;
}