/* 
 *     Author:  srtry
 *     Created: 2025-05-25T06:50:42+09:00
 *     Coding:  utf-8-unix
 */

use proconio::input;
use std::io::{stdout,Write,BufWriter};

fn main() {
    input!{
        n:usize,
        mut a:[usize;n]
    }

    let out = stdout();
    let mut out = BufWriter::new(out.lock());
    
    let mut ans:usize = 0;
    let mut cnt:usize = 0;
    let mut idx:usize = n-1;
    loop {
        if (idx == 0) {
            if (a[idx] != n-cnt) {
                ans += 1;
            }
            break;
        }
        if (a[idx] == n-cnt) {
            cnt += 1;
            idx -= 1;
        } else {
            ans += 1;
            idx -= 1;
        }
    }

    write!(out, "{}", ans).unwrap();
}