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

const int nmax = 16000;
vector<int> v[nmax+5];
int cost[nmax+5],dp[nmax+5],Max=-1000005;
int dfs(int s, int p)
{
    int sum = cost[s];
    for (int i = 0; i<v[s].size(); i++)
        if (v[s][i]!=p)
            sum+=dfs(v[s][i],s);
    Max = max(Max,sum);
    return max(sum,0);
}

int main()
{
    freopen("asmax.in","r",stdin);
    freopen("asmax.out","w",stdout);
    int n,x,y;
    scanf("%d",&n);
    for (int i = 1; i<=n; i++)
        scanf("%d",&cost[i]);
    for (int i = 1; i<n; i++)
    {
        scanf("%d%d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    dfs(1,0);
    printf("%d",Max);
}