#include <bits/stdc++.h>
#include "testlib.h"
using namespace std;

#define MOD 998244353

int main() {
    registerValidation();
	long long N = inf.readLong(2LL, 200000LL, "N");
	inf.readEoln();
	vector<long long> A(N);
	for (int i = 0; i < N; i++) {
	    if (i != 0) inf.readSpace();
	    A[i] = inf.readLong(1LL, 1000000000LL, "A");
	}
	inf.readEoln();
	inf.readEof();

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

	cout << ans << endl;
}