#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<ctime>
#include<cmath>
#include<algorithm>
#define FILE "gamebeta"
typedef long long ll;
typedef double lf;
namespace IO{
	char buf[1<<15],*fs,*ft;
	inline char getc(){return (fs==ft&&(ft=(fs=buf)+fread(buf,1,1<<15,stdin),fs==ft))?0:*fs++;}
	inline int read(){
		int x=0,rev=0,ch=getc();
		while(ch<'0'||ch>'9'){if(ch=='-')rev=1;ch=getc();}
		while(ch>='0'&&ch<='9'){x=(x<<1)+(x<<3)+ch-'0';ch=getc();}
		return rev?-x:x;
	}
}using namespace IO;
const int MAXN(500000),D(50),INF(1<<30);
int f[MAXN+D];
int n,c[MAXN+D];
namespace Tree{
	struct edge{
		int y,next;
		static int tot;
	}e[MAXN*2+D];
	int head[MAXN+D],edge::tot;
	inline void connect(int x,int y){
		int& k=edge::tot;
		e[++k].next=head[x];e[head[x]=k].y=y;
		e[++k].next=head[y];e[head[y]=k].y=x;
	}
	inline int max(int x,int y){return x>y?x:y;}
	inline bool by_time(const int& x,const int& y){return f[x]>f[y];}
	void dp(){
		static int par[MAXN+D],size[MAXN+D];
		static int stack[MAXN+D],top=0;
		static bool oped[MAXN+D];
		static int son[MAXN+D];
		oped[stack[++top]=1]=false;
		while(top){
			int x=stack[top];
			if(oped[x]){
				size[par[x]]+=size[x];
				int tot=0;
				for(int i=head[x],y;i;i=e[i].next)
					if((y=e[i].y)!=par[x])
						son[++tot]=y;
				std::sort(son+1,son+tot+1,by_time);
				f[x]=c[x];
				for(int i=1,cur=0;i<=tot;i++){
					f[x]=max(f[x],1+cur+f[son[i]]);
					cur+=size[son[i]]<<1;
				}
				top--;
			}
			else{
				oped[x]=true;
				size[x]=1;
				for(int i=head[x],y;i;i=e[i].next)
					if((y=e[i].y)!=par[x])
						par[y]=x,oped[stack[++top]=y]=false;
			}
		}
		printf("%d\n",max(f[1],c[1]+(n-1<<1)));
	}
}
void init(){
	n=read();
	for(int i=1;i<=n;i++)
		c[i]=read();
	for(int i=1;i<n;i++)
		Tree::connect(read(),read());
}
int main(){
	freopen(FILE".in","r",stdin);
	freopen(FILE".out","w",stdout);
	init();
	Tree::dp();
	return 0;
}