#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define all(x) x.begin(), x.end()
using namespace std;
const int N = 2e5 + 7;
const int MOD = 1e9 + 7; // 998244353;
const int INF = 1e9 + 7;
const long long INFLL = 1e18 + 7;
template <class X, class Y> bool minimize(X &a, Y b) {
if (a > b) return a = b, true;
return false;
}
template <class X, class Y> bool maximize(X &a, Y b) {
if (a < b) return a = b, true;
return false;
}
struct Disjoint_set {
vector<int> lab;
Disjoint_set(int n = 0) {
lab.assign(n + 7, -1);
}
int root(int u) {
return lab[u] < 0 ? u : lab[u] = root(lab[u]);
}
bool unite(int u, int v) {
u = root(u); v = root(v);
if (u == v) return false;
if (lab[u] > lab[v]) swap(u, v);
lab[u] += lab[v];
lab[v] = u;
return true;
}
};
const int MAX = 1e7;
int n;
int a[N];
int nxt[MAX + 7];
vector<pair<int, int>> val[MAX];
void solve(void) {
cin >> n;
for (int i = 1; i <= n; i ++) cin >> a[i];
sort(a + 1, a + n + 1);
for (int i = 1; i <= n; i ++) nxt[a[i]] = i;
for (int i = MAX; i > 0; i --) if (nxt[i] == 0) {
nxt[i] = nxt[i + 1];
}
for (int i = 1; i <= n; i ++) {
if (nxt[a[i]] != i) val[0].emplace_back(i, nxt[a[i]]);
if (nxt[a[i] + 1]) val[(a[nxt[a[i] + 1]] % a[i])].emplace_back(i, nxt[a[i] + 1]);
for (int j = a[i] * 2; j <= MAX; j += a[i]) {
if (!nxt[j]) break;
if (j + a[i] >= a[nxt[j]]) {
assert(a[nxt[j]] - j >= 0);
val[a[nxt[j]] - j].emplace_back(i, nxt[j]);
}
}
}
long long res = 0;
Disjoint_set dsu(n);
for (int i = 0; i < MAX; i ++) {
for (pair<int, int> x: val[i]) if (dsu.unite(x.fi, x.se)) {
// cout << x.se << " " << x.fi << ' ' << i << '\n';
res += i;
}
}
cout << res;
}
int main(void) {
cin.tie(0)->sync_with_stdio(0);
int test = 1;
// cin >> test;
while (test --) {
solve();
}
return 0;
}
