#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define mp make_pair
#define pb push_back
#define F first
#define S second
#define debug(x) std::cout << #x << ": " << x << "\n"
#define all(v) v.begin(), v.end()
#define li(i,a,b) for (int (i) = (a); (i) < (b); (i)++)
#define endl '\n'
#define mem(name,val) memset(name,val,sizeof(name))
#define min(a,b) (a<=b ? a : b)
#define max(a,b) (a>=b ? a : b)
//using u64 = uint64_t;
//using u128 = __uint128_t;
const int nmax = 1e5+3;
vector<int> P;
int p[nmax],sz[nmax];
int get(int a){
return p[a]=(p[a]==a?a:get(p[a]));
}
void uni(int a, int b){
a=get(a);
b=get(b);
if(a==b)return;
if(sz[a]<sz[b])swap(a,b);
p[b]=a;
sz[a]+=sz[b];
}
int foo(int a, int b){
return min(a%b, b%a);
}
struct Compare {
bool operator()(const pii &e1, const pii &e2) const {
return foo(P[e1.F], P[e1.S]) > foo(P[e2.F], P[e2.S]);
}
};
int main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
li(i,0,nmax){p[i]=i;sz[i]=1;}
int n,a;
cin>>n;
li(i,0,n){
cin>>a;P.pb(a);
if(a==0){
cout<<0;
return 0;
}
}
sort(all(P));
priority_queue<pii, vector<pii>, Compare> pq;
li(i,0,n){
for(int j=0; j<=P[n-1]; j+=P[i]){
auto it = lower_bound(all(P),j);
if(it==P.end()){
pq.push({i,n-1});
break;
}
int idx = it-P.begin();
pq.push({i,idx});
pq.push({i,min(idx+1,n-1)});
}
}
int cnt =0;
ll res = 0;
while(!pq.empty() && cnt<n-1){
auto [i,j] = pq.top();
pq.pop();
if(get(i)==get(j)) continue;
uni(i,j);
res+=foo(P[j],P[i]);
cnt++;
pq.push({i,min(j+1,n-1)});
}
cout<<res;
return 0;
}
