//https://yukicoder.me/problems/no/2938

fun main(){
    val n = readln().toInt()
    val a = readln().split(" ").map { it.toInt()}
    var z: Int


    var ans: Int = 0
    fun ab(x: Int, y: Int): Int {
        if (x >= y){
            z = x-y
        }else z = y-x
        return z
    }

    for (i in 0..<n){
        for (j in 0..<n)
            ans = ans + (ab(i,j) * ab(a[i],a[j]))
    }
    println(ans)
}