import sys; sys.setrecursionlimit(2 * 10 ** 5)

N = int(input())
g = [[] for _ in range(N)]
for _ in range(N - 1):
	u, v = map(int, input().split())
	u -= 1
	v -= 1
	g[u].append(v)
	g[v].append(u)
a = list(map(int, input().split()))


vis = [False] * N
ans = 0
def dfs(u):
	global ans
	d = []
	vis[u] = True
	res = 0
	s = 1
	j = -1
	l = []
	r = []
	for i in g[u]:
		if vis[i]:
			if a[i] > a[u]:
				j = len(l)
				l.append(0)
			if a[i] < a[u]:
				j = len(r) + N
				r.append(0)
		else:
			t = dfs(i)
			s += t
			if a[i] > a[u]:
				l.append(t)
			if a[i] < a[u]:
				r.append(t)
	if j != -1:
		if j < N:
			l[j] = N - s
		else:
			r[j - N] = N - s
	ans += (sum(l) ** 2 - sum(i ** 2 for i in l)) // 2 + (sum(r) ** 2 - sum(i ** 2 for i in r)) // 2
	return s

dfs(0)
print(ans % 998244353)