import java.util.Scanner;

public class Main{
	public static void main(String[] args){
		Scanner scn = new Scanner(System.in);
		int N = scn.nextInt();
		int A[] = new int[N];
		int sum = 0;
		
		for(int i = 0; i < N; i++){
			A[i] = scn.nextInt();
		}
		
		for(int i = 0; i < N; i++){
			for(int j = 0; j < N; j++){
				sum += Math.abs(i - j) * Math.abs(A[i] - A[j]);
			}
		}
		
		System.out.println(sum);
	}
}