import java.io.*; import java.util.*; public class Main { static final int MOD = 998244353; public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int n = sc.nextInt(); HashMap counts = new HashMap<>(); int ans = 0; for (int i = 0; i < n; i++) { int x = sc.nextInt(); if (counts.containsKey(x - 1)) { ans += counts.get(x - 1); ans %= MOD; counts.put(x, (counts.getOrDefault(x, 0) + counts.get(x - 1) + 1) % MOD); } else { counts.put(x, 1); } } System.out.println(ans); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }