#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
using namespace std;
const int M = 1e7 + 5, N = 1 << 19;
int p[N], r[N], lwrbnd[M];
vector<int> nodes;
vector<pair<int, int>> edges[M];
int ufind(int v) {
if (v != p[v]) p[v] = ufind(p[v]);
return p[v];
}
signed main() {
cin.sync_with_stdio(0);
cin.tie(0);
int n, lim = 0;
cin >> n;
for (int i = 0, v; i < n; i++) {
cin >> v;
if (!lwrbnd[v]) {
lwrbnd[v] = 1;
nodes.push_back(v);
lim = max(lim, v);
}
}
iota(p, p + N, 0);
sort(nodes.begin(), nodes.end());
long long ans = 0;
int cur = 0;
for (int i = 0; i < nodes.size(); i++) {
for (; cur <= nodes[i]; cur++) {
lwrbnd[cur] = i;
}
}
for (; cur <= lim; cur++) lwrbnd[cur] = -1;
// for (int v : nodes) cout << v << " "; cout << "\n";
// for (int i = 0; i < 14; i++) cout << lwrbnd[i] << " "; cout << "\n";
for (int i = 0, v, res; i < nodes.size(); i++) {
v = nodes[i];
res = lwrbnd[v+1];
if (res != -1) edges[nodes[res] % v].push_back({i, res});
for (int vi = 2 * v; vi <= lim; vi += v) {
res = lwrbnd[vi];
if (res != -1) edges[nodes[res] % v].push_back({i, res});
}
}
for (int i = 0; i < M; i++) {
for (auto& [a, b] : edges[i]) {
a = ufind(a);
b = ufind(b);
// cout << a << " " << b << " -> " << cost << "\n";
if (a != b) {
ans += i;
if (r[a] < r[b]) swap(a, b);
if (r[a] == r[b]) r[a]++;
p[b] = a;
}
}
}
cout << ans << "\n";
return 0;
}
