#include <bits/stdc++.h>
using namespace std;
#define N 100005
#define se second
#define fi first
int n, par[N];
long long res = 0;
vector<int> p;
struct ii
{
int u, v, w;
bool operator < (ii o){
return w < o.w;
}
};
int find(int u){
if (u == par[u]) return u;
return par[u] = find(par[u]);
}
void unin(int u, int v, int w){
u = find(u);
v = find(v);
if (u == v) return;
par[u] = v;
res += w;
}
void sub1(){
for (int i = 0; i < n; i++) par[i] = i;
vector<ii> eg;
for (int i = 0; i < n; i++){
for (int j = 0; j < n; j++){
if (i == j) continue;
eg.push_back({i, j, p[j] % p[i]});
}
}
sort(eg.begin(), eg.end());
for (auto x : eg){
unin(x.u, x.v, x.w);
}
cout << res;
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cin >> n;
for (int i = 1; i <= n; i++){
int val;
cin >> val;
p.push_back(val);
}
if (n <= 1000){
sub1();
return 0;
}
sort(p.begin(), p.end());
p.resize(unique(p.begin(), p.end()) - p.begin());
int ma = p.back();
vector<int> near(ma + 1, -1);
vector<vector<pair<int, int>>> eg(ma + 1);
for (int i = 0; i < (int) p.size(); i++){
par[i] = i;
near[p[i]] = i;
}
for (int i = ma - 1; i >= 0; i--){
if (near[i] == -1) near[i] = near[i + 1];
}
for (int i = 0; i < (int) p.size(); i++){
eg[(p[i + 1] % p[i])].push_back({i, i + 1});
for (int j = 2 * p[i]; j <= ma; j += p[i]){
int pos = near[j];
if (pos == -1) continue;
eg[(p[pos] % p[i])].push_back({i, pos});
}
}
for (int i = 0; i <= ma; i++){
for (auto x : eg[i]){
unin(x.fi, x.se, i);
}
}
cout << res;
return 0;
}
