#include <bits/stdc++.h>
using namespace std;
struct edge{
int weight,n1,n2;
};
struct DSU {
vector<int> e; void init(int N) { e = vector<int>(N,-1); }
int get(int x) { return e[x] < 0 ? x : e[x] = get(e[x]); }
bool sameSet(int a, int b) { return get(a) == get(b); }
int size(int x) { return -e[get(x)]; }
bool unite(int x, int y) {
x = get(x), y = get(y); if (x == y) return 0;
if (e[x] > e[y]) swap(x,y);
e[x] += e[y]; e[y] = x; return 1;
}
};
bool cmp(edge x, edge y){
return x.weight < y.weight;
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
int n; cin >> n;
vector<int> cards(n); vector<edge> edges;
for(int i = 0;i<n;++i) cin >> cards[i];
sort(cards.begin(),cards.end());
cards.resize(unique(cards.begin(),cards.end()) - cards.begin());
n = cards.size();
for(int i = 0;i<n-1;++i){
for(int j = cards[i];j<=cards.back();j+=cards[i]){
int it = lower_bound(cards.begin()+i+1,cards.end(),j)-cards.begin();
if(it >= n || cards[it]-j > cards[i]) continue;
edge ne; ne.weight = cards[it]-j; ne.n1 = i; ne.n2 = it;
edges.push_back(ne);
}
}
DSU d; d.init(n); long long ans = 0;
sort(edges.begin(),edges.end(),cmp);
for(auto e : edges){
if(d.unite(e.n1,e.n2)){
//cout << e.n1 << " " << e.n2 << " " << e.weight << "\n";
ans += e.weight;
}
}
cout << ans << "\n";
return 0;
}
