n=int(input())
a=list(map(int,input().split()))
e=[[] for i in range(n)]
for i in range(n-1):
  u,v=map(int,input().split())
  u-=1
  v-=1
  e[u]+=[v]
  e[v]+=[u]
M=998244353
i2=pow(2,M-2,M)
u=[0]*n
v=[0]*n
q=[0]
ans=0
while len(q)>0:
  s=q[-1]
  if v[s]==0:
    v[s]=1
    for t in e[s]:
      if v[t]==0:
        q+=[t]
  else:
    f=0
    for t in e[s]:
      if v[t]==0:
        f=1
        u[s]+=u[t]*a[s]
        u[s]%=M
    u[s]+=a[s]
    u[s]%=M
    ans+=u[s]
    ans%=M
    a2=0
    for t in e[s]:
      if v[t]==0:
        a2+=u[t]
        a2%=M
    a2=a2**2
    for t in e[s]:
      if v[t]==0:
        a2-=u[t]**2
        a2%=M
    a2*=i2
    a2%=M
    ans+=a2*a[s]
    ans%=M
    v[s]=0
    q.pop()
ans-=sum(a)
ans%=M
print(ans)