use proconio::input;

const INF: usize = 10_usize.pow(6);

fn main() {
    input! {
        (n, q): (usize, usize),
        aa: [usize; n],
        bb: [usize; q],
    }

    let mut dp = vec![INF; n];
    dp[0] = 0;
    for &b in &bb {
        let mut next_dp = vec![INF; n];

        let mut to_right = INF;
        for (i, &a) in aa.iter().enumerate() {
            to_right = to_right.min(dp[i] + n - 1 - i);

            if a == b {
                next_dp[i] = next_dp[i].min(to_right - (n - 1 - i));
            }
        }

        let mut to_left = INF;
        for (i, &a) in aa.iter().enumerate().rev() {
            to_left = to_left.min(dp[i] + i);

            if a == b {
                next_dp[i] = next_dp[i].min(to_left - i);
            }
        }

        dp = next_dp;
    }

    let ans = *dp.iter().min().unwrap();
    println!("{}", ans);
}