#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<cstring>
#include<string>
#include<cstdlib>
#include<stack>
#include<vector>
#include<queue>
#include<deque>
#include<map>
#include<set>
using namespace std;
#define lck_max(a,b) ((a)>(b)?(a):(b))
#define lck_min(a,b) ((a)<(b)?(a):(b))
#define maxn 16002
typedef long long LL;
LL sum[maxn],n;
LL head[maxn<<1],cnt=0;
vector<LL>son[maxn];
LL w[maxn],ans=-maxn;
struct hh
{
    LL nex,to;
}t[maxn<<1];
inline LL read()
{
    LL kr=1,xs=0;
    char ls;
    ls=getchar();
    while(!isdigit(ls))
    {
        if(!(ls^45))
            kr=-1;
        ls=getchar();
    }
    while(isdigit(ls))
    {
        xs=(xs<<1)+(xs<<3)+(ls^48);
        ls=getchar();
    }
    return xs*kr;
}
LL u,v;
inline void add(LL nex,LL to)
{
    t[++cnt].nex=head[nex];
    t[cnt].to=to;
    head[nex]=cnt;
}
inline void dfs(LL u,LL fa)
{
    for(LL i=head[u];i;i=t[i].nex)
    {
        LL v=t[i].to;
        if(v==fa) continue;
        son[u].push_back(v);
        dfs(v,u);
    }
    if(son[u].size())
    {
        for(LL j=0;j<son[u].size();j++)
        {
            if(w[son[u][j]]<0) continue;
            w[u]+=w[son[u][j]];
        }
    }
    w[u]+=sum[u];
    ans=lck_max(ans,w[u]);
return ;
}
int main()
{
    //freopen("t.in","r",stdin);
    n=read();
    for(LL i=1;i<=n;i++)
        sum[i]=read();
    for(LL i=1;i<n;i++)
    {
        u=read();v=read();add(u,v);add(v,u);
    }
    dfs(1,0);
    printf("%lld\n",ans);
return 0;
}