use std::cmp;
use std::collections::HashMap;
use std::io::*;
use std::io::{stderr, stdin};
use std::str::FromStr;

fn main() {
    let cin = stdin();
    let mut sc = Scanner::new(cin.lock());

    let n = sc.next::<usize>();
    let q = sc.next::<usize>();
    let a = sc.vec::<usize>(n);

    let mut mp = HashMap::new();
    for i in 0..n {
        mp.entry(a[i]).or_insert(vec![]).push(i);
    }

    let mut dp = vec![vec![2e9 as usize; n]; q + 1];
    dp[0][0] = 0;
    let mut prv = 0;
    for i in 0..q {
        let b = sc.next::<usize>();
        if i == 0 {
            for j in mp.get(&b).unwrap() {
                dp[i + 1][*j] = cmp::min(dp[i + 1][*j], dp[i][0] + *j);
            }
        } else {
            for j in mp.get(&prv).unwrap() {
                for k in mp.get(&b).unwrap() {
                    dp[i + 1][*k] = cmp::min(
                        dp[i + 1][*k],
                        dp[i][*j] + (cmp::max(*j, *k) - cmp::min(*j, *k)),
                    );
                }
            }
        }
        prv = b;
    }

    let mut mi = usize::MAX;
    for i in mp.get(&prv).unwrap() {
        mi = cmp::min(mi, dp[q][*i]);
    }
    println!("{}", mi);
}

pub struct Scanner<R: std::io::Read> {
    reader: R,
}

#[allow(dead_code)]
impl<R: Read> Scanner<R> {
    fn new(reader: R) -> Scanner<R> {
        Scanner { reader: reader }
    }

    fn read<T: FromStr>(&mut self) -> Option<T> {
        let token = self
            .reader
            .by_ref()
            .bytes()
            .map(|c| c.unwrap() as char)
            .skip_while(|c| c.is_whitespace())
            .take_while(|c| !c.is_whitespace())
            .collect::<String>();
        if token.is_empty() {
            None
        } else {
            token.parse::<T>().ok()
        }
    }

    fn next<T: FromStr>(&mut self) -> T {
        if let Some(s) = self.read() {
            s
        } else {
            writeln!(stderr(), "Terminated with EOF").unwrap();
            std::process::exit(0);
        }
    }

    fn vec<T: FromStr>(&mut self, n: usize) -> Vec<T> {
        (0..n).map(|_| self.next()).collect()
    }

    fn char(&mut self) -> char {
        self.next::<String>().chars().next().unwrap()
    }
}