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

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

const int N=16002;
vector<int> a[N];
bool viz[N];
int s[N],scor[N];
int n,m;

void dfs(int x)
{
    viz[x]=true;
    scor[x]=s[x];
    for(auto y:a[x])
    {
        if(!viz[y])
        {
            dfs(y);
            if(scor[y]>0)
                scor[x]+=scor[y];
        }
    }
}


int main()
{
    int i;
    int x,y;
    fin>>n;
    for(i=1;i<=n;i++)
        fin>>s[i];
    while(fin>>x>>y)
    {
        a[x].push_back(y);
        a[y].push_back(x);
    }
    dfs(1);
    sort(scor+1,scor+n+1);
    fout<<scor[n];
    return 0;
}