const INF: isize = 1isize << 60;
const LIMIT: usize = 10000;

fn main() {
    let mut n = String::new();
    std::io::stdin().read_line(&mut n).ok();
    let n: usize = n.trim().parse().unwrap();
    let mut y = String::new();
    std::io::stdin().read_line(&mut y).ok();
    let y: Vec<isize> = y.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();

    let mut dp = vec![vec![INF; LIMIT+1]; n];
    for i in 0..=LIMIT {
        dp[0][i] = (i as isize - y[0]).abs();
    }
    for i in 1..n {
        let mut cost = INF;
        for j in 0..=LIMIT {
            cost = cost.min(dp[i-1][j] + (y[i] - j as isize).abs());
            dp[i][j] = dp[i][j].min(cost);
            if (j as isize) < y[i] {
                cost -= 1;
            } else {
                cost += 1;
            }
        }
    }
    println!("{}", dp[n-1].iter().min().unwrap());
}