#include <bits/stdc++.h>
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)

using namespace std;
using mint = modint998244353;

int main() {
    cin.tie(nullptr) -> sync_with_stdio(false);
    
    int n;
    cin >> n;
    
    vector<int> a(n);
    rep(i, n) cin >> a[i];
    
    vector<vector<int>> to(n);
    rep(i, n-1) {
        int u, v;
        cin >> u >> v;
        --u; --v;
        to[u].push_back(v);
        to[v].push_back(u);
    }
    
    mint ans;
    vector<mint> dp(n);
    auto dfs = [&](auto& f, int v, int p=-1) -> void {
        dp[v] = a[v];
        for (int u : to[v]) {
            if (u == p) continue;
            f(f, u, v);
            ans += dp[v]*dp[u];
            dp[v] += dp[u]*a[v];
        }
    };
    dfs(dfs, 0);
    
    cout << ans.val() << '\n';
    
    return 0;
}