#include <fstream>
#include <vector>

using namespace std;

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

const int N = 16000;
int viz[N + 1];
int suma[N + 1];
int val[N + 1];
vector<int> a[N + 1];

void asmax(int x) {
    viz[x] = 1;
    suma[x] = val[x];
    for (auto y: a[x]) {
        if (!viz[y]) {
            asmax(y);
            if (suma[y] > 0) {
                suma[x] += suma[y];
            }
        }
    }
}

int main() {
    int n;
    in >> n;
    int x, y;
    for (int i = 1; i <= n; i++) {
        in >> val[i];
    }

    while (in >> x >> y) {
        a[x].push_back(y);
        a[y].push_back(x);
    }

    asmax(1);
    int max = INT32_MIN;
    for (int i = 1; i <= n; i++) {
        if (suma[i] > max) {
            max = suma[i];
        }
    }
    out << max;
    return 0;
}