#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i = a; i <= b; i++)
#define FOD(i,a,b) for(int i = a; i >= b; i--)
//#define int long long
#define fi first
#define se second
#define pb push_back
#define ll long long
#define ull unsigned long long
#define db double
#define lcm(a,b) a / __gcd(a, b) * b
#define ii pair<int,int>
#define iii pair<int,pair<int,int>>
#define iv pair<pair<int,int>,pair<int,int>>
#define sq(a) (a) * (a)
#define MASK(i) (1LL << i)
#define task "task"
const int inf = 1e9;
const ll INF = 1e18;
const int mod = 1e9 + 7;
const int N = 1e5 + 5;
const int P = 1e7;
int n;
vector<int> a;
int best[P + 5];
vector<ii> candi[P + 5];
int root[N], sze[N];
void init() {
FOR(i, 0, (int)a.size() - 1) {
root[i] = i;
sze[i] = 1;
}
}
int anc(int u) {
return root[u] == u ? u : root[u] = anc(root[u]);
}
ll ans;
void join(int u, int v, int w) {
u = anc(u);
v = anc(v);
if(u == v) return;
ans += w;
if(sze[u] < sze[v]) swap(u, v);
root[v] = u;
sze[u] += sze[v];
}
void KhoiLe() {
sort(a.begin(), a.end());
a.erase(unique(a.begin(), a.end()), a.end());
int mx = a.back();
FOR(i, 1, mx) best[i] = -1;
FOR(i, 0, (int)a.size() - 1) best[a[i]] = i;
FOD(i, mx - 1, 1) if(best[i] == -1) best[i] = best[i + 1];
FOR(i, 0, (int)a.size() - 2) {
candi[a[i + 1] % a[i]].pb({i, i + 1});
for(int j = 2 * a[i]; j <= mx; j += a[i]) {
if(best[j] != -1) candi[a[best[j]] % a[i]].pb({i, best[j]});
}
}
init();
FOR(i, 0, mx) for(auto H : candi[i]) join(H.fi, H.se, i);
cout << ans << '\n';
}
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int test = 1;
// cin >> test;
while(test--) {
cin >> n;
FOR(i, 1, n) {
int x;
cin >> x;
a.pb(x);
}
KhoiLe();
}
}
