#include <fstream>
#include <vector>

using namespace std;

ifstream fin("asmax.in");
ofstream fout("asmax.out");

int n, c[16005], x, y, dp[16005], maxim = -1e9;
vector<int> G[16005];
bool v[16005];

void dfs(int nod) {
    v[nod] = true;
    dp[nod] = c[nod];
    for(auto i : G[nod]) {
        if(!v[i]) {
            dfs(i);
            if(dp[i] + dp[nod] > dp[nod]) {
                dp[nod] = dp[i] + dp[nod];
            }
        }
    }
}

int main() {
    fin >> n;
    for(int i = 1; i <= n; i++) {
        fin >> c[i];
    }
    for(int i = 1; i < n; i++) {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    dfs(1);
    for(int i = 1; i <= n; i++) {
        maxim = max(maxim, dp[i]);
    }
    fout << maxim;
    return 0;
}