#include <fstream>
#include <vector>
using namespace std;

using VI = vector<int>;
using VB = vector<bool>;
using VVI = vector<VI>;

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

VVI G;
VI sz, val;
VB v;
int n, mx;

void CitireDate();
void DFS(int x);

int main()
{
    CitireDate();
    DFS(1);
    fout << mx;

    return 0;
}

void DFS(int x)
{
    v[x] = true;
    sz[x] = val[x];

    for(int y : G[x])
    {
        if(v[y]) continue;
        DFS(y);
        
        if(sz[y] > 0)
            sz[x] += sz[y];
    }
    mx = max(sz[x], mx);
}

void CitireDate()
{
    fin >> n;
    G = VVI(n + 1);
    sz = val = VI(n + 1);
    v = VB(n + 1);

    for(int i = 1; i <= n; ++i)
        fin >> val[i];

    for(int x, y; fin >> x >> y;)
    {
        G[x].push_back(y);
        G[y].push_back(x);
    }
}