/**
 *    Author : pradumn
**/
#include<bits/stdc++.h>
using namespace std;
#define Fast_io ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define ll long long
#define M 1000000007
#define fo(i,n) for(i=0;i<n;i++)
#define pb push_back
#define mp make_pair
#define deb(c) cout<<c<<endl
#define umap unordered_map
#define pqueue priority_queue
#define all(v) v.begin(),v.end()
#define ft first
#define sc second
#define nl "\n"
#define mxe  *max_element
#define mne  *min_element
#define gcd  __gcd
#define sz(x) (int)(x.size())
#define rev(x) reverse(all(x))
#define itr(it, a) for(auto it = a.begin(); it != a.end(); it++)
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pi;
typedef vector<vi> vvi;
typedef map<int,int> mi;
void init_code()
{
  Fast_io;
  #ifndef ONLINE_JUDGE
    freopen("Input.txt","r",stdin);
    freopen("Output.txt","w",stdout);
    freopen("error.txt","w",stderr);
  #endif
}

void func()
{
 float n;
 cin>>n;
 n=n/100;
 cout<<ceil(n);
}
int main()
{
    init_code();
double start1 = (double)clock();
// int t;
// cin>>t;
// while(t--)
func();
double stop1 =(double)clock();
double duration = (stop1-start1)/CLOCKS_PER_SEC;
#ifndef ONLINE_JUDGE
cerr << "Time: " << duration << endl;
#endif
}
#include <bits/stdc++.h>
#define rep(i,n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int,int>;

int main() {
  int n;
  cin >> n;
  vector<ll> a(n);
  ll sum = 0;
  rep(i, n) {
    cin >> a[i];
    sum += a[i];
  }

  ll ans = 0;
  for (int i = n-1; i >= 0; i--) {
    sum -=a[i];
    ans += (n-1) * a[i] * a[i];
    ans -= 2 * sum * a[i]; 
  }
  cout << ans << endl;
  return 0;
}