#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
using ll=long long;
using ld=long double;
using ull=unsigned long long;
using pii=pair<int,int>;
using pll=pair<ll,ll>;
using mint=modint998244353;
const ll INF=1ll<<60;
int main(){
  int N; cin>>N;
  ll A[N];
  for(int i=0;i<N;i++)cin>>A[i];
  ll ans=0;
  for(int i=0;i<N;i++){
    for(int j=0;j<N;j++)ans+=abs(i-j)*abs(A[i]-A[j]);
  }
  cout<<ans<<endl;
}