#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

const ll modc = 998244353;

int main(){

    ll ans=1, N;
    cin >> N;
    vector<ll> A(N);
    for (int i=0; i<N; i++) cin >> A[i];

    for (int i=0; i<N-1; i++){
        ans *= min(A[i], A[i+1]);
        ans %= modc;
    }

    cout << ans << endl;

    return 0;
}