#include <iostream>
#include <vector>
#include <algorithm>
#include <tuple>
#include <climits>
using namespace std;
const int MAX_VAL = 10000000;
const int T = 1000;
vector<int> parent;
int find(int x) {
if (parent[x] != x) {
parent[x] = find(parent[x]);
}
return parent[x];
}
void unite(int x, int y) {
x = find(x);
y = find(y);
if (x != y) {
parent[y] = x;
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
vector<int> P(n);
for (int i = 0; i < n; i++) {
cin >> P[i];
}
sort(P.begin(), P.end());
P.erase(unique(P.begin(), P.end()), P.end());
int m = P.size();
if (m == 0) {
cout << 0 << endl;
return 0;
}
if (m == 1) {
cout << 0 << endl;
return 0;
}
if (P[0] == 1) {
cout << 0 << endl;
return 0;
}
vector<int> next(MAX_VAL + 2, 0);
vector<int> pos(MAX_VAL + 1, -1);
for (int i = 0; i < m; i++) {
if (P[i] <= MAX_VAL) {
pos[P[i]] = i;
}
}
for (int i = MAX_VAL; i >= 1; i--) {
next[i] = next[i + 1];
if (pos[i] != -1) {
next[i] = i;
}
}
parent.resize(m);
for (int i = 0; i < m; i++) {
parent[i] = i;
}
for (int i = 0; i < m; i++) {
int a = P[i];
for (int k = 2; (long long)k * a <= MAX_VAL; k++) {
int target = k * a;
if (target > MAX_VAL) break;
if (next[target] == target) {
int j = pos[target];
if (j != -1) {
if (find(i) != find(j)) {
unite(i, j);
}
}
}
}
}
int comps = 0;
for (int i = 0; i < m; i++) {
if (find(i) == i) {
comps++;
}
}
if (comps == 1) {
cout << 0 << endl;
return 0;
}
vector<tuple<int, int, int>> edges;
for (int i = 0; i < m; i++) {
int a = P[i];
if (a > T) break;
for (int k = 1; (long long)k * a <= MAX_VAL; k++) {
int L = k * a;
int R = (k + 1) * a - 1;
if (L > MAX_VAL) break;
if (next[L] == 0) continue;
if (next[L] > R) continue;
int b = next[L];
int j = pos[b];
if (j == -1) continue;
int w = b - L;
edges.push_back({i, j, w});
}
}
for (int i = 0; i < m - 1; i++) {
int w = P[i + 1] - P[i];
edges.push_back({i, i + 1, w});
}
sort(edges.begin(), edges.end(), [](const auto& a, const auto& b) {
return get<2>(a) < get<2>(b);
});
long long ans = 0;
for (const auto& e : edges) {
int u = get<0>(e);
int v = get<1>(e);
int w = get<2>(e);
if (find(u) != find(v)) {
ans += w;
unite(u, v);
comps--;
if (comps == 1) break;
}
}
cout << ans << endl;
return 0;
}
