#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <tuple>
#include <cmath>
#include <numeric>
#include <functional>
#include <cassert>
#include <atcoder/modint>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

template<typename T>
vector<vector<T>> vec2d(int n, int m, T v){
    return vector<vector<T>>(n, vector<T>(m, v));
}

template<typename T>
vector<vector<vector<T>>> vec3d(int n, int m, int k, T v){
    return vector<vector<vector<T>>>(n, vector<vector<T>>(m, vector<T>(k, v)));
}

template<typename T>
void print_vector(vector<T> v, char delimiter=' '){
    if(v.empty()) {
        cout << endl;
        return;
    }
    for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter;
    cout << v.back() << endl;
}

using mint = atcoder::modint998244353;

ostream& operator<<(ostream& os, const mint& m){
    os << m.val();
    return os;
}

int n;
vector<int> g[5000];
bool ok[5000];

using Arr = array<mint, 2>;

array<array<mint, 2>, 5000> dp1;
array<array<mint, 2>, 5000> dp2;

Arr op(Arr a, Arr b){
    Arr ans = {{mint(0), mint(0)}};
    for(int x = 0; x < 2; x++){
        for(int y = 0; y < 2; y++){
            // 切る場合
            ans[x] += a[x]*b[y];
            // つなぐ場合
            ans[max(x, y)] += a[x]*b[y];
        }
    }
    return ans;
}


void dfs1(int v, int par){
    if(ok[v]) {
        dp1[v][0] = 0;
        dp1[v][1] = 1;
    }else{
        dp1[v][0] = 1;
        dp1[v][1] = 0;
    }
    for(int to: g[v]){
        if(to == par) continue;
        dfs1(to, v);
        Arr nx = op(dp1[v], dp1[to]);
        for(int x = 0; x < 2; x++) dp1[v][x] = nx[x];
    }
}


Arr e() {
    return {{mint(1), mint(0)}};
}

void dfs2(int v, int par, Arr from_par){
    vector<int> children;
    for(int to: g[v]){
        if(to == par) continue;
        children.push_back(to);
    }
    Arr cur = {{mint(0), mint(0)}};
    if(ok[v]) cur[1] = 1;
    else cur[0] = 1;
    int m = children.size();
    vector<Arr> from_left(m+1);
    if(v == 0){
        from_left[0] = cur;
        dp2[v] = dp1[v];
    }else{
        from_left[0] = op(cur, from_par);
        dp2[v] = op(dp1[v], from_par);
    }
    
    for(int i = 0; i < m; i++){
        int to = children[i];
        from_left[i+1] = op(from_left[i], dp1[to]);
    }
    Arr from_right = e();
    for(int i = m-1; i >= 0; i--){
        int to = children[i];
        Arr propagate = {{mint(0), mint(0)}};
        for(int x = 0; x < 2; x++){
            for(int y = 0; y < 2; y++){
                propagate[max(x, y)] += from_left[i][x]*from_right[y];
            }
        }
        dfs2(to, v, propagate);
        from_right = op(from_right, dp1[to]);
        // Arr p = from_left[0];
        // for(int j = 0; j < m; j++){
        //     if(i == j) continue;
        //     p = op(p, dp1[children[j]]);
        // }
        // dfs2(to, v, p);
    }
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    int n; cin >> n;
    vector<int> a(n);
    for(int i = 0; i < n; i++) cin >> a[i];
    for(int i = 0; i < n-1; i++){
        int u, v; cin >> u >> v; u--; v--;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    mint ans = 0;
    for(int x = 1000; x >= 1; x--){
        for(int i = 0; i < n; i++){
            if(a[i] >= x) ok[i] = true;
        }
        dfs1(0, -1);
        dfs2(0, -1, e());
        for(int i = 0; i < n; i++){
            ans += dp2[i][1];
        }
    }
    cout << ans << endl;
}