#include <bits/stdc++.h>
using namespace std;

struct dat {
  int Count;
  long long totDis;
  dat() : Count(0), totDis(0) {}
};

int main() {
  int N; cin >> N;
  long long Ans = 0;
  vector<int> A(N);
  vector<dat> L(501), R(501);

  for (int i = 0; i < N; i++) {
    cin >> A.at(i);
    R.at(A.at(i)).Count++;
    R.at(A.at(i)).totDis += i;
  }

  for (int i = 0; i < N; i++) {
    for (int j = 1; j < 501; j++) {
      int diff = abs(A.at(i) - j);
      Ans += ((long long)i * L.at(j).Count - L.at(j).totDis) * diff;
      Ans += (R.at(j).totDis - (long long)i * R.at(j).Count) * diff;
    }

    R.at(A.at(i)).Count--;
    R.at(A.at(i)).totDis -= i;
    L.at(A.at(i)).Count++;
    L.at(A.at(i)).totDis += i;
  }

  cout << Ans << endl;
}