#include <bits/stdc++.h>
#define all(v) begin(v), end(v)
#define ii pair<int, int>
#define fi first
#define se second
#define siz(v) (int)(v).size()
#define lli pair<long long, int>
#define dbg(x) "[" #x " = " << x << "]"
#define BIT(x, i) (((x) >> (i)) & 1)
#define MASK(i) (1LL << (i))
#define left __left
#define right __right
using namespace std;
bool M1;
const long long inf = 1e18 + 123;
const int mod = 1e9 + 7, infINT = 1e9 + 1321, LOG = 32;
template<class X, class Y> bool minimize(X &x, const Y &y){return x > y ? x = y, 1: 0;}
template<class X, class Y> bool maximize(X &x, const Y &y){return x < y ? x = y, 1: 0;}
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
#define ll long long
ll ran(ll l, ll r){
return uniform_int_distribution<ll>(l, r)(rd);
}
void add(int &a, const int &b){
a += b;
if (a >= mod) a -= mod;
}
void sub(int &a, const int &b){
a -= b;
if (a < 0) a += mod;
}
int mul(const int &a, const int &b){
return 1LL * a * 1LL * b % mod;
}
int bin_pow(int a, long long k){
int res = 1;
while(k){
if (k & 1) res = mul(res, a);
k >>= 1; a = mul(a, a);
}
return res;
}
struct dsu{
int n;
vector<int > par, sz;
dsu(int _n = 0): n(_n){
par.assign(n + 1, 0);
sz.assign(n + 1, 1);
for(int i = 1; i <= n; i++) par[i] = i;
}
int root(int v){
return v == par[v] ? v: par[v] = root(par[v]);
}
bool join(int u, int v){
u = root(u), v = root(v);
if (u == v) return 0;
if (sz[u] < sz[v]) swap(u, v);
par[v] = u; sz[u] += sz[v];
return 1;
}
};
const int MAXN = 1e5 + 5, MAXV = 1e7 + 3;
int numVal, pos[MAXV];
vector<int > val;
vector<array<int, 3 > > edge;
void input(){
cin >> numVal;
for(int i = 1; i <= numVal; i++){
int x; cin >> x;
val.push_back(x);
}
}
long long mst(){
long long sum = 0;
dsu mySet(numVal);
sort(all(edge));
for(array<int, 3> &e: edge){
if (mySet.join(e[1] + 1, e[2] + 1)) sum += e[0];
}
return sum;
}
void solve(){
sort(all(val));
val.resize(unique(all(val)) - begin(val));
memset(pos, -1, sizeof pos);
numVal = siz(val);
for(int i = 0; i < numVal; i++){
pos[val[i]] = i;
}
for(int i = MAXV - 1; i > 0; i--){
if (pos[i - 1] == -1) pos[i - 1] = pos[i];
}
for(int i = 0; i < numVal; i++){
int x = val[i];
for(int k = 0; x * k < MAXV; k++){
if (pos[x * k] != -1) edge.push_back({val[pos[x * k]] - x * k, i, pos[x * k]});
if (pos[x * k + 1] != -1 && x * k + 1 < MAXV) edge.push_back({val[pos[x * k + 1]] - x * k, i, pos[x * k + 1]});
}
}
cout << mst() << '\n';
}
bool M2;
signed main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define task "test"
if (fopen(task".inp", "r")){
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
input();
solve();
cerr << (&M2 - &M1) / 1048576 << " mb\n";
cerr << (1.0 * clock()) / CLOCKS_PER_SEC << ".s\n";
}
