import sys
input = sys.stdin.readline

N = int(input())
G = [[] for i in range(N)]
for i in range(N - 1):
    u, v = map(int, input().split())
    u, v = u - 1, v - 1
    G[u].append(v)
    G[v].append(u)
    
A = list(map(int, input().split()))
mod = 998244353
    
def non_rec_dfs(s):
    stack = []
    stack.append(s)
    par = [-1] * N
    sz = [1] * N
    ans = 0
    while stack:
        u = stack.pop()
        if u >= 0:
            stack.append(~u)
            for v in G[u]:
                if v == par[u]:
                    continue
                par[v] = u
                stack.append(v)
        else:
            u = ~u
            for v in G[u]:
                if v == par[u]:
                    continue
                sz[u] += sz[v]
                
            p2, p1, m2, m1 = 0, 0, 0, 0
            for v in G[u]:
                val = sz[v]
                if v == par[u]:
                    val = N - sz[u]
                if A[v] > A[u]:
                    p2 += val ** 2
                    p1 += val
                elif A[v] < A[u]:
                    m2 += val ** 2
                    m1 += val
            ans += (p1**2 - p2)//2 + (m1**2 - m2)//2
            ans %= mod

    return ans

print(non_rec_dfs(0))