#include <bits/stdc++.h>
using namespace std;
typedef long long lo;
#define fi first
#define se second
#define endl "\n"
#define pb push_back
#define fio() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define FOR for(int i=1;i<=n;i++)
#define mid ((start+end)/2)
#define ort ((bas+son)/2)
#define _ << " " <<
const lo inf = 1000000000;
const lo li = 500005;
const lo mod = 1000000007;
int n,m,a[li],k,flag,t,fa[li],vis[10000005],mx[10000005],ind[10000005];
long long cev;
string s;
vector<pair<int,int>> v[10000002];
set<pair<int,int>> st;
inline int dsu(int x){
if(x==fa[x])return x;
return fa[x]=dsu(fa[x]);
}
int main(void){
fio();
cin>>n;
FOR{
fa[i]=i;
cin>>a[i];
mx[a[i]]=a[i];
}
for(int i=10000000-1;i>=1;i--){
if(!mx[i])mx[i]=mx[i+1];
}
sort(a+1,a+n+1);
FOR{
if(!ind[a[i]])ind[a[i]]=i;
}
FOR{
if(a[i]==a[i-1]){
v[0].pb({i-1,i});
continue;
}
if(mx[a[i]+1] && mx[a[i]*2]!=mx[a[i]+1])v[mx[a[i]+1]-a[i]].pb({i,ind[mx[a[i]+1]]});
for(int j=a[i]*2;j<=10000000;j+=a[i]){
vis[j]=i;
if(mx[j] && mx[j]!=mx[j+a[i]])v[mx[j]-j].pb({i,ind[mx[j]]});
}
}
for(int i=0;i<=10000000;i++){
for(auto go:v[i]){
int x=go.fi;
int y=go.se;
if(dsu(x)==dsu(y))continue;
fa[dsu(x)]=dsu(y);
cev+=i;
}
}
cout<<cev<<endl;
return 0;
}
