#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int main()
{
    int n;
    cin >> n;
    vector<int> a(n);
    rep(i,n) cin >> a[i];
    vector<vector<int>> g(n);
    rep(i,n-1) {
        int u, v;
        cin >> u >> v;
        --u;--v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    vector<mint> dp(n);
    mint ans = 0;
    auto dfs = [&](auto dfs, int u, int p = -1) -> void {
        mint sum = 0;
        for(int v : g[u]) {
            if(v==p) continue;
            dfs(dfs, v, u);
            ans += sum*a[u]*dp[v];
            sum += dp[v];
            dp[u] += dp[v] * a[u];
        }
        ans += dp[u];
        dp[u] += a[u];
    };
    dfs(dfs, 0);
    cout << ans.val() << endl;
    return 0;
}