#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <deque>
#include <iomanip>
using namespace std;
typedef long long ll;
#define rep(i,n) for (int i=0;i < (int)(n);i++)


ll pow(ll a, ll b){
   ll res = 1LL;
   for (int i = 0; i < b;i++){
      res *= a;
   }
   return res;
}
void solve(){
  int n;
  cin >> n;
  vector<int> a(n);
  rep(i,n) cin >> a[i];
  map<ll,ll> mp;
  ll ans = 0;
  for (int i = 0; i < n;i++){
   mp[a[i]]++;
  }
  for (int i = 0; i < n;i++){
   for (auto [x,y]:mp){
      ans += pow(a[i],x)*y;
   }
  }
  cout << ans << endl;

  return;
}

  

int main(){
  int tt = 1;
  //cin >> tt;
  while(tt--){
	  solve();
  }
  return 0;
}