#include<bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using mint=modint998244353; //1000000007;
using ll=long long;
using pp=pair<int,int>;
#define sr string 
#define vc vector
#define fi first
#define se second
#define rep(i,n) for(int i=0;i<(int)n;i++)
#define pb push_back
#define all(v) v.begin(),v.end()
#define pque priority_queue
#define bpc(a) __builtin_popcount(a)
int main(){
  int n;cin>>n;
  vc<int>x(n); rep(i,n)cin>>x[i];
  vc v(n,vc<int>(0));
  rep(i,n-1){
    int a,b;cin>>a>>b; 
    a--;b--;
    v[a].pb(b); v[b].pb(a);
  }
  mint ans=0;
  auto f=[&](auto f,int a,int p)->mint{
    mint res=0;
    for(auto au:v[a])if(au!=p){
      mint t=f(f,au,a);
      ans+=res*t*x[a];
      res+=t;
    }
    ans+=res*x[a];
    res=(res+1)*x[a];
    return res;
  };
  f(f,0,-1);
  cout<<ans.val();
}