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

int n, a;
long long m;
const long long M = 998244353;
map<int, pair<int, long long>> Mp;

int main() {
	cin >> n;

	for (int i = 0; i < n; i++) {
		cin >> a;

		if (Mp.find(a - 1) == Mp.end()) {
			if (Mp.find(a) == Mp.end()) {
				Mp[a] = { 1, 0 };
			}
			else {
				Mp[a].first++;
			}
		}
		else {
			long long u = (Mp[a - 1].second + Mp[a - 1].first) % M;

			if (Mp.find(a) == Mp.end()) {
				Mp[a] = { 1, u };
			}
			else {
				Mp[a].first++;
				Mp[a].second = (Mp[a].second + u) % M;
			}

			m = (m + u) % M;
		}
	}

	cout << m << endl;
}