#include <fstream>
#include <vector>
using namespace std;
ifstream in("asmax.in");
ofstream out("asmax.out");
const int nmax = 16001;
vector<int>g[nmax];
long long val[nmax];
long long s[nmax];
int f[nmax];

void dfs(int node)
{
    f[node] = 1;
    s[node] += val[node];
    for(int i = 0; i < g[node].size(); i++)
    {
        int vecin = g[node][i];
        if(f[vecin] == 0)
            dfs(vecin);
    }
}

int main()
{
    int n;
    in>>n;
    long long stotal = 0;
    for(int i = 1; i <= n; i++)
    {
        in>>val[i];
        stotal += val[i];
    }
    for(int i = 1; i <= n - 1; i++)
    {
        int a,b;
        in>>a>>b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    dfs(1);
    int mini = 0;
    for(int i = 1; i <= n; i++)
        if(s[i] < 0 && mini > s[i])
            mini = s[i];
    out<<stotal - mini;
    return 0;
}