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

void solve(){
    vector<int> a;
    int n, x, soma = 0;
    cin >> n;
    for(int i = 0; i < n; i++){
        cin >> x;
        a.push_back(x);
    }

    int quant = n - 1;

    for(int i = 0; i < n; i++){
        soma = soma + quant * a[i];
    }
    cout << soma << endl;
    cout << endl;
}

int main(){
    solve();
    return 0;
}