#include <bits/stdc++.h>
using namespace std;
using LL = long long;
constexpr LL mod = 998244353;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    vector<int> a(n);
    for (int &ai : a) {
        cin >> ai;
    }
    LL ans = 1;
    for (int i = 1; i < n; i += 1) {
        ans = ans * min(a[i - 1], a[i]) % mod;
    }
    cout << ans;
}