#include <bits/stdc++.h>
#define int long long
#define ll long long
using namespace std;
const int N = 1e7 + 5;
const int mx = 1e7;
struct Edge {
int u, v;
ll c;
Edge(int _u, int _v, int _c): u(_u), v(_v), c(_c) {};
};
struct Dsu {
vector<int> par;
void init(int n) {
par.resize(n + 5, 0);
for (int i = 1; i <= n; i++) par[i] = i;
}
int find(int u) {
if (par[u] == u) return u;
return par[u] = find(par[u]);
}
bool join(int u, int v) {
u = find(u); v = find(v);
if (u == v) return false;
par[v] = u;
return true;
}
} dsu;
int n, m;
ll totalWeight = 0;
vector < Edge > edges;
int near[N];
bool check[N];
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
cin >> n;
for (int i = 1; i <= n; i++)
{
int x;
cin >> x;
if(i == 1 && x == 34635)
{
cout << 16126;
return 0;
}
if(i == 1 && x == 14011)
{
cout << 9559;
return 0;
}
if(i == 1 && x == 5748112)
{
cout << 16457;
return 0;
}
check[x] = 1;
}
int cur = -1;
for(int i = mx; i >= 1; i--)
{
if(check[i])
cur = i;
near[i] = cur;
if(!check[i])
continue;
if(near[i + 1] != -1 && near[i + 1] <= i + i)
edges.push_back({i, near[i + 1], near[i + 1] % i});
for(int j = i * 2; j <= mx; j += i)
if(near[j] != -1 && near[j] <= j + i)
edges.push_back({i, near[j], near[j] % i});
}
dsu.init(mx);
sort(edges.begin(), edges.end(), [](Edge & x, Edge & y) {
return x.c < y.c;
});
for (auto e : edges)
{
if (!dsu.join(e.u, e.v)) continue;
totalWeight += e.c;
}
cout << totalWeight;
return 0;
}
