#include<iostream>
#include<fstream>
#include<vector>
#include<stack>
#define DX 16010
using namespace std;
fstream fin("asmax.in",ios::in),fout("asmax.out",ios::out);
typedef vector<int> VI;
VI v[DX];
int c[DX],maxim=-(DX*1000),n;
void dfs(int nod,int pre)
{
    for(auto x:v[nod])
    {
        if(x!=pre)
        {
            dfs(x,nod);
            if(c[x]>0)
            {
                c[nod]+=c[x];
            }
        }
    }
    maxim=max(maxim,c[nod]);
}
int main()
{
    int a,b,i;
    fin>>n;
    for(i=1;i<=n;i++) fin>>c[i];
    while(fin>>a>>b)
    {
        v[a].push_back(b);
        v[b].push_back(a);
    }
    dfs(1,0);
    fout<<maxim<<"\n";
}