import strutils,sequtils
var m=998244353
var n=stdin.readLine.parseint
var g=newSeqWith(n,newSeq[int](0))
for i in 0..<n-1:
 var u=stdin.readline.split.map(parseint).mapit(it-1)
 g[u[0]].add(u[1])
 g[u[1]].add(u[0])
var a=stdin.readLine.split.map(parseInt)
var ans=0
proc dfs(x,par:int):int=
 result=1
 var tl,tu=0
 for y in g[x]:
  if y==par: continue
  var sz=dfs(y,x)
  result+=sz
  if a[y]<a[x]:
   ans+=(tl*sz)mod m
   tl+=sz
  if a[x]<a[y]:
   ans+=(tu*sz)mod m
   tu+=sz
 if par!= -1:
  if a[par]<a[x]: ans+=(tl*(n-result))mod m
  if a[x]<a[par]: ans+=(tu*(n-result))mod m
 ans=ans mod m
discard dfs(0,-1)
echo ans