from collections import defaultdict

N = int(input())

S = list(map(int,input().split()))

connected = [[] for _ in range(N)]
for _ in range(N-1):
	a,b = map(int,input().split())
	a -= 1
	b -= 1
	connected[a].append(b)
	connected[b].append(a)

dp = [0]*N

S_ = defaultdict(list)
for i,s in enumerate(S):
	S_[s].append(i)
events = [[k,v] for k,v in S_.items()]
events.sort()

for s,arr in events:
	tasks = []
	for i in arr:
		tmp = 0
		for j in connected[i]:
			tmp = max(tmp, dp[j])
		tasks.append((i,tmp + S[i]))
	for i,res in tasks:
		dp[i] = res
ans = max(dp)
print(ans)