#include<bits/stdc++.h>
using namespace std;
#define ALL(x) x.begin(),x.end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define debug(v) cout<<#v<<":";for(auto x:v){cout<<x<<' ';}cout<<endl;
#define mod 1000000007
// using ll=long long;
// const int INF=1000000000;
// const ll LINF=1001002003004005006ll;
int dx[]={1,0,-1,0},dy[]={0,1,0,-1};
// ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
template<class T>bool chmax(T &a,const T &b){if(a<b){a=b;return true;}return false;}
template<class T>bool chmin(T &a,const T &b){if(b<a){a=b;return true;}return false;}

struct IOSetup{
    IOSetup(){
        cin.tie(0);
        ios::sync_with_stdio(0);
        cout<<fixed<<setprecision(12);
    }
} iosetup;
 
template<typename T1,typename T2>
ostream &operator<<(ostream &os,const pair<T1,T2>&p){
    os<<p.first<<" "<<p.second;
    return os;
}
 
template<typename T>
ostream &operator<<(ostream &os,const vector<T>&v){
    for(int i=0;i<(int)v.size();i++) os<<v[i]<<(i+1==(int)v.size()?"":" ");
    return os;
}

template<typename T1,typename T2>
istream &operator>>(istream &is,pair<T1,T2>&p){
    is>>p.first>>p.second;
    return is;
}

template<typename T>
istream &operator>>(istream &is,vector<T>&v){
    for(T &x:v)is>>x;
    return is;
}
// 2^127 = 170141183460469231731687303715884105728 ~ 10^38
using ll=__int128;
 
ostream &operator<<(ostream &os,const __int128 n){
    if(n==0){
        os<<0;
        return os;
    }
    __int128 num=n;
    bool neg=false;
    if(num<0)neg=true,num=-num;
    string res="";
    while(num>0){
        res.push_back('0'+num%10);
        num/=10;
    }
    if(neg) res.push_back('-');
    reverse(begin(res),end(res));
    os<<res;
    return os;
}
 
istream &operator>>(istream &is,__int128 &n){
    string s;
    is>>s;
    int idx=0;
    bool neg=false;
    if(s[0]=='-')neg=true,idx++;
    n=0;
    for(;idx<(int)s.size();idx++){
        n=10*n+s[idx]-'0';
    }
    if(neg) n=-n;
    return is;
}
 
__int128 abs128(__int128 x){
    return x<0?-x:x;
}
 
__int128 gcd128(__int128 a,__int128 b){
    if(a==0) return b;
    if(b==0) return a;
    return b>0?gcd128(b,a%b):a;
}
 



template<typename Monoid>
struct SegmentTree{
    using F=function<Monoid(Monoid,Monoid)>;
    int sz;
    vector<Monoid> seg;
    const F f;
    const Monoid gen;
    SegmentTree(int n,const F f,const Monoid &gen):f(f),gen(gen){
        sz=1;
        while(sz<n)sz<<=1;
        seg.assign(2*sz,gen);
    }
    void set(int k,const Monoid &x){
        seg[k+sz]=x;
    }
    void build(){
        for(int k=sz-1;k>0;k--) seg[k]=f(seg[2*k],seg[2*k+1]);
    }
    void update(int k,const Monoid &x){
        k+=sz;
        seg[k]=x;
        while(k>>=1) seg[k]=f(seg[2*k],seg[2*k+1]);
    }
   // [a,b)
    Monoid query(int a,int b){
        Monoid L=gen,R=gen;
        for(a+=sz,b+=sz;a<b;a>>=1,b>>=1){
            if(a&1) L=f(L,seg[a++]);
            if(b&1) R=f(seg[--b],R);
        }
        return f(L,R);
    }
    Monoid operator[](const int &k)const {
       return seg[k+sz];
    }
};

ll f(ll a,ll b){
    return a+b;
}

const int M=500000;

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

    SegmentTree<ll> s1(M,f,0),s2(M,f,0);
    rep(i,M){
        s1.set(i,b[i]);
        s2.set(i,b[i]*i);
    }
    s1.build();
    s2.build();
    ll res=0;
    for(int i=1;i<M;i++){
        ll p=0;
        for(int j=i;j<M;j+=i){
            res+=b[i]*(s2.query(p,j)-s1.query(p,j)*p);
            p=j;
        }
    }
    cout<<res<<endl;
    return 0;
}