use std::collections::BTreeMap;

fn main() {
    let n: usize = {
        let mut line: String = String::new();
        std::io::stdin().read_line(&mut line).unwrap();
        line.trim().parse().unwrap()
    };

    let A: Vec<i64> = {
        let mut line: String = String::new();
        std::io::stdin().read_line(&mut line).unwrap();
        line.split_whitespace()
            .map(|x| x.parse().unwrap())
            .collect()
    };

    let modx = 998244353;
    let mut ans=0;

    let mut DP: BTreeMap<i64, i64> = BTreeMap::new();

    for i in 0..n{
        let a=A[i];

        let mut x=0;

        if DP.contains_key(&(a-1)){
            x=DP[&(a-1)];
        }

        ans=(ans+x)%modx;

        if DP.contains_key(&(a)){
            DP.insert(a,(DP[&(a)]+x+1)%modx);
        }
        else{
            DP.insert(a,(x+1)%modx);
        }
    }

    println!("{}",ans);
}