import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

class Graph(object):
	def __init__(self):
		self.graph = defaultdict(list)

	def __len__(self):
		return len(self.graph)

	def add_edge(self, a, b):
		self.graph[a].append(b)

def DFS(G, DPA, DPB, B, visit, node):
	for i in G.graph[node]:
		if visit[i] != 1:
			visit[i] = 1
			DFS(G, DPA, DPB, B, visit, i)
			DPA[node] += max(DPA[i], DPB[i])
			DPB[node] += max(DPA[i], DPB[i] + B[node] + B[i])

#処理内容
def main():
	N = int(input())
	A = getlist()
	B = getlist()
	G = Graph()
	for i in range(N - 1):
		u, v = getlist()
		u -= 1; v -= 1
		G.add_edge(u, v)
		G.add_edge(v, u)

	#DFS
	DPA = [A[i] for i in range(N)]
	DPB = [0] * N
	visit = [0] * N
	visit[0] = 1
	DFS(G, DPA, DPB, B, visit, 0)
	ans = max(DPA[0], DPB[0])
	print(ans)


if __name__ == '__main__':
	main()