#include <cstdio>
#include <vector>

using namespace std;

vector<int> g[16001];
bool vis[16001];
bool root[16001];
int v[16001];

int sol = -0x3f3f3f3f;

int dfs(int node)
{
    vis[node] = 1;
    int s = v[node];
    for (unsigned i = 0; i < g[node].size(); i++)
        if (!vis[g[node][i]]) {
            s += dfs(g[node][i]);
        }

    if (s < 0)
        s = 0;

    if (s > sol)
        sol = s;
    return s;
}

int main()
{
    FILE *in = fopen("asmax.in", "r");
    FILE *out = fopen("asmax.out", "w");

    int n;
    fscanf(in, "%d", &n);
    int nmax = -2000, nstart = 1;
    for (int i = 1; i <= n; ++i)
    {
        fscanf(in, "%d", &v[i]);
        if (v[i] > nmax)
            nmax = v[i], nstart = i;
    }
    for (int x, y, i = 1; i < n; ++i)
    {
        fscanf(in, "%d%d", &x, &y);
        g[x].push_back(y);
        g[y].push_back(x);
    }

    dfs(1);
    fprintf(out, "%d\n", sol);

    return 0;
}