#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) begin(x), end(x)
#define sz(x) (int)x.size()
#define pb push_back
struct DSU{
vector<int> link, size;
int cc;
DSU(int n){
link.resize(n+1, 0);
size.resize(n+1, 1);
for(int i=1; i<=n; i++) link[i] = i;
cc = n;
}
int find(int x){
if(x != link[x]) link[x] = find(link[x]);
return link[x];
}
bool same(int a, int b){
return find(a) == find(b);
}
void merge(int a, int b){
if(same(a, b)) return;
a = find(a); b = find(b);
if(size[a] > size[b]) swap(a, b);
link[a] = b;
size[b] += size[a];
cc--;
}
};
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
int n; cin >> n;
vector<int> v(1e7+1);
int m = 0;
for(int i=1; i<=n; i++){
int x; cin >> x;
v[x] = 1;
m = max(m, x);
}
vector<int> mp(m+1);
int c = 0;
for(int i=1; i<=m; i++){
if(v[i] == 1){
mp[i] = ++c;
}
}
n = c;
DSU D(n);
for(int i=1; i<=m; i++){
if(v[i] == 1){
for(int j=2*i; j<=m; j+=i){
if(v[j] == 1){
D.merge(mp[i], mp[j]);
}
}
}
}
vector<int> w[m+1];
for(int i=1; i<=m; i++){
if(v[i] == 1){
w[i].pb(i);
for(int j=2*i; j<=m; j+=i){
if(v[j] == 0) v[j] = 2;
w[j].pb(i);
}
}
}
vector<int> p(m+1);
c = 0;
for(int i=1; i<=m; i++){
if(v[i] == 0) continue;
p[i] = c;
c = i;
}
vector<array<int, 3>> vec;
for(int i=1; i<=m; i++){
if(v[i] == 1){
int j = p[i];
if(j == 0) continue;
while(true){
vec.pb({i-j, i, j});
if(v[j] == 1) break;
j = p[j];
}
}
}
sort(all(vec));
ll ans = 0LL;
for(auto [d, i, j]: vec){
if(D.cc == 1) break;
for(auto k: w[j]){
if(i%k == d){
if(!D.same(mp[i], mp[k])){
D.merge(mp[i], mp[k]);
ans += d;
}
}
if(D.cc == 1) break;
}
}
cout << ans;
}
