package main

import . "fmt"

func abs(a int)int {
	if a<0 {
		return -a
	} else {
		return a
	}
}

func main() {
	var n int
	Scan(&n)
	if n>100 {
		// evil
		return
	}
	a:=make([]int,n,n)
	for i:=range a {
		Scan(&a[i])
	}
	s:=0
	for i,x:=range a {
		for j,y:=range a {
			s+=abs(i-j)*abs(x-y)
		}
	}
	Println(s)
}