#include <cstdio>
#include <vector>
using namespace std;
int max_v(int a, int b){ return a > b ? a : b; }
//vector<int> cost; // 1,000,000
vector<vector<int>> adj;
//vector<bool> vi;
 
int cost[1000001], ans = 0;
bool vi[1000001];
int dfs(int vn, int p_max){
	vi[vn] = 1;
	int ret = cost[vn], subsum=p_max, p = max_v(cost[vn], p_max), c;
 
	for(int& v : adj[vn])
		if(!vi[v]){
			c = dfs(v, p);
			ret = max_v(ret, c);
			subsum += c;
		}
	ans = max_v(ans, subsum);
	return ret;
}
 
int main() {
	int N,u,v,i;
	scanf("%d",&N);
	adj.resize(N+1);
	//cost.resize(N), 
	//vi = vector<bool>(N, false);
	for(i=0;i<N;i++) scanf("%d",&cost[i]);
	for(i=0;i<N-1;i++){
		scanf("%d%d",&u,&v);
		u--,v--;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	dfs(0,0);
	printf("%d",ans);
	return 0;
}

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