use std::io::*;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let n: usize = itr.next().unwrap().parse().unwrap();
    let a: Vec<usize> = (0..n)
        .map(|_| itr.next().unwrap().parse::<usize>().unwrap() - 1)
        .collect();

    let mut used = vec![false; n + 1];
    let mut ans = 0;
    for i in (0..n).rev() {
        let mut j = a[i] + 1;
        while j < n && used[j] {
            j += 1;
        }
        if j != n {
            used[j] = true;
            ans += i + 1;
        } else if !used[a[i]] {
            used[a[i]] = true;
        } else {
            for k in 0..n {
                if !used[k] {
                    used[k] = true;
                    break;
                }
            }
            ans -= i + 1;
        }
    }
    println!("{}", ans);
}