#include<bits/stdc++.h>
using namespace std;
#define fs first
#define sc second
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define ALL(A) A.begin(),A.end()
#define RALL(A) A.rbegin(),A.rend()
typedef long long ll;
typedef pair<ll,ll> P;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
template<typename T> T gcd(T a,T b){return b?gcd(b,a%b):a;}
const ll MOD=1000000007;
const ll LINF=1ll<<60;
const int INF=1<<30;
int dx[]={1,0,-1,0,1,-1,1,-1};
int dy[]={0,1,0,-1,1,-1,-1,1};


int main(){
    int n;cin >> n;
    vector<ll> a(n);
    vector<ll> c(1<<18,0),x(1<<18 + 1,0),y(1<<18 + 1, 0);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
        c[a[i]]++;
    }
    for (int i = 0; i < 1<<18; i++) {
        x[i+1] = x[i] + c[i];
        y[i+1] = y[i] + i * c[i];
    }
    ll ans = 0;
    for (int i = 1; i < 1<<18; i++) {
        if(c[i]){
            for (int j = i; j < 1<<18; j+=i) {
                ll t = j / i - 1;
                ans += c[i] * ((y[j] - y[j-i]) - (x[j] - x[j-i]) * i * t);
            }
        }
    }
    cout << ans << endl;
    return 0;
}