#include <iostream>
using namespace std;
using ll = long long;
ll const m = 998244353;
int main () {
    int N;
    cin >> N;
    ll pre;
    cin >> pre;
    ll ans = 1;
    for (int i = 1; i < N; i ++) {
        ll a;
        cin >> a;
        ans *= min(a, pre);
        ans %= m;
        pre = a;
    }
    cout << ans << endl;
}