from collections import deque
MOD=998244353
def pairs(arr):
    add=0
    squ=0
    for i in arr:
        add+=i
        squ+=i*i
    return (add*add-squ)//2
N=int(input())
tree=[set() for i in range(N)]
for i in range(N-1):
    U,V=map(int,input().split())
    tree[U-1].add(V-1)
    tree[V-1].add(U-1)
A=list(map(int,input().split()))
top=[]
vert=deque([0])
dp=[-1]*N
while len(vert)>0:
    pos=vert.popleft()
    top.append(pos)
    dp[pos]=0
    for i in tree[pos]:
        if dp[i]==-1:
            vert.append(i)
for i in reversed(top):
    for j in tree[i]:
        dp[i]+=dp[j]
    dp[i]+=1
ans=0
for i in range(N):
    rem=-1
    less=[]
    gre=[]
    for j in tree[i]:
        if dp[i]<dp[j]:
            rem=j
            continue
        if A[i]<A[j]:
            less.append(dp[j])
        elif A[i]>A[j]:
            gre.append(dp[j])
    if rem!=-1:
        if A[i]<A[rem]:
            less.append(N-dp[i])
        elif A[i]>A[rem]:
            gre.append(N-dp[i])
    ans+=pairs(less)+pairs(gre)
    ans%=MOD
print(ans)