#include <bits/stdc++.h>
using namespace std;
#define ar array
#define ll long long
const int inf = 2e9;
const int N = 1e7 + 2;
const ll linf = 1e13;
int here[N] = {}, V[N], Z[N];
int find(int x) {
int y = x;
while (V[x] > 0)
x = V[x];
while (x != y)
y = exchange(V[y], x);
return x;
}
int unite(int x, int y) {
// cout << x << " " << y << " ";
x = find(x);
y = find(y);
// cout << x << " " << y << " " << Z[x] << " " << Z[y] << "\n";
if (x == y)
return 0;
if (V[x] > V[y])
swap(x, y);
V[x] += V[y];
V[y] = x;
Z[x] |= Z[y];
return 1;
}
int good(int x) {
return Z[find(x)];
}
void solve() {
// for (int i = 1; i < N;i++)
// V[i] = -1, Z[i] = 0;
int n;
cin >> n;
vector<int> A(n);
vector<ar<int, 3>> edges;
for (int i = 1; i <= n;i++) {
int x; cin >> x;
here[x] = 1;
A[i - 1] = x;
Z[x] = 1;
}
sort(A.begin(), A.end());
A.erase(unique(A.begin(), A.end()), A.end());
set<int> st;
for (int i = 1; i < N;i++)
if (here[i])
for (int d = i; d < N; d += i)
if (here[d] || st.count(d) == 0)
st.insert(d), unite(i, d);
for (int x : A) {
auto it = st.lower_bound(x + 1);
if (it == st.end())
continue;
int y = *it;
edges.push_back({y - x, x, y});
}
ll ans = 0;
sort(edges.begin(), edges.end());
for (auto [w, x, y] : edges)
if (unite(x, y))
ans += w;
cout << ans;
}
int32_t main() {
#ifdef Behruz
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
ios :: sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
solve();
return 0;
}
