// [+]
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 1e5 + 5, MAX = 1e7 + 5;
int n, a[N], mx = 0;
vector<pair<int, int>> edges[MAX];
int nxt[MAX];
int p[MAX], num[MAX];
inline int find(int x) {
if (p[x] != x)
p[x] = find(p[x]);
return p[x];
}
bool join(int x, int y) {
x = find(x);
y = find(y);
if (x == y) return false;
if (num[x] < num[y])
swap(x, y);
num[x] += num[y];
p[y] = x;
return true;
}
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n;
for (int i = 1; i <= n; i++)
cin >> a[i], mx = max(a[i], mx);
iota(p + 1, p + mx + 1, 1);
fill(num + 1, num + mx + 1, 1);
sort(a + 1, a + n + 1);
n = unique(a + 1, a + n + 1) - a - 1;
memset(nxt, 63, sizeof nxt);
for (int i = 1; i <= n; i++)
nxt[a[i]] = a[i];
for (int i = mx; i > 0; i--)
nxt[i] = min(nxt[i], nxt[i + 1]);
for (int i = 1; i <= n; i++) {
if (nxt[a[i] + 1] < a[i] * 2)
edges[nxt[a[i] + 1] - a[i]].emplace_back(nxt[a[i] + 1], a[i]);
for (int j = a[i] * 2; j <= mx; j += a[i])
if (nxt[j] < j + a[i])
edges[nxt[j] - j].emplace_back(a[i], nxt[j]);
}
ll ans = 0;
for (int i = 0; i < mx; i++)
for (const auto &elem: edges[i])
if (join(elem.first, elem.second))
ans += i;
cout << ans;
return 0;
}
