import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int remein = 0;
        long count = 0;
        for (int i = 0; i < n; i++) {
            int x = sc.nextInt() + remein;
            remein = x - 1;
            count += Math.abs(remein);
        }
        System.out.println(count);
    }
}