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<Integer, Integer> 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, counts.getOrDefault(x, 0) + 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();
    }
}