#include <bits/stdc++.h>
#ifdef __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() {
    int n;
    cin >> n;
    
    vector<int> a(n);
    rep(i, n) cin >> a[i];
    
    mint ans = 1;
    rep(i, n-1) ans *= min(a[i], a[i+1]);
    
    cout << ans.val() << '\n';
    
    return 0;
}