import sys
input = sys.stdin.readline

mod=998244353

N=int(input())

E=[[] for i in range(N)]

for i in range(N-1):
    u,v=map(int,input().split())
    u-=1
    v-=1
    E[u].append(v)
    E[v].append(u)

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

# 木のHL分解+LCA

ROOT=0

QUE=[ROOT] 
Parent=[-1]*N
Parent[ROOT]=N # ROOTの親を定めておく.
Child=[[] for i in range(N)]
TOP_SORT=[] # トポロジカルソート

while QUE: # トポロジカルソートと同時に親を見つける
    x=QUE.pop()
    TOP_SORT.append(x)
    for to in E[x]:
        if Parent[to]==-1:
            Parent[to]=x
            Child[x].append(to)
            QUE.append(to)

Children=[1]*N

ANS=0

for x in TOP_SORT[::-1]: #（自分を含む）子ノードの数を調べる
    if x==ROOT:
        break
    Children[Parent[x]]+=Children[x]

for i in range(N):
    if Child[i]==[]:
        continue
    #if Parent[i]==N:
    #    continue
    LOW=[]
    HIGH=[]
    a=A[i]

    for c in Child[i]:
        if A[c]<a:
            LOW.append(Children[c])
        elif A[c]>a:
            HIGH.append(Children[c])

    p=Parent[i]
    if p!=N:
        if A[p]<a:
            LOW.append(N-Children[i])
        elif A[p]>a:
            HIGH.append(N-Children[i])

    #print(i,LOW,HIGH)

    S=sum(LOW)
    for l in LOW:
        S-=l
        ANS+=l*S

    S=sum(HIGH)
    for h in HIGH:
        S-=h
        ANS+=h*S

    ANS%=mod

print(ANS)