#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,m,n) for(int i=m; i<n; ++i)
#define repl(i,m,n) for(ll i=m; i<n; ++i)

int main(){
    vector powered(10, vector(10, 1LL));
    rep(i, 1, 9){
        rep(j, 1, 9){
            rep(k, 0, j){
                powered[i][j] *= ll(i);
            }
        }
    }

    int N;
    cin >> N;

    vector<ll> A(N);
    for(ll &a : A) cin >> a;

    vector cnt(10, 0);
    rep(i, 0, N){
        cnt[A[i]]++;
    }

    ll ans = 0LL;
    rep(i, 1, 9){
        rep(j, 1, 9){
            repl(k, 0, cnt[i]*cnt[j]){
                ans += powered[i][j];
            }
        }
    }

    cout << ans << endl;
    return 0;
}