#include <bits/stdc++.h>
using namespace std;
#define int long long
vector <int> arr = {};
vector <int> cnt(1e7+2);
vector <int> ind(1e7+2);
vector <vector <int>> di(1e7+2);
vector <int> dsu(100002, -1);
vector <int> siz(100002, 1);
int findroot(int cur) {
if(dsu[cur] == -1) {
return cur;
}
return dsu[cur] = findroot(dsu[cur]);
}
signed main() {
//your code goes here
int n;
cin >> n;
vector <int> arr = {};
for(int i = 0; i < n; i++) {
int num;
cin >> num;
arr.push_back(num);
cnt[num] = 1;
ind[num] = i;
}
for(int i = 0; i <= 1e2; i++) {
if(cnt[i] != 1) {
continue;
}
for(int j = (i*2); j <= 1e2; j+=i) {
di[j].push_back(i);
}
}
sort(arr.begin(), arr.end());
vector <vector <int>> e = {};
for(int i = 0; i < n; i++) {
if(i == 0) {
continue;
}
int v = arr[i];
int v2 = arr[i-1];
for(int j = v; j >= v2; j--) {
int v3 = di[j].size();
if(v3 > 0) {
int v4 = v-j;
for(auto i:di[j]) {
e.push_back({i, v, v4});
}
break;
}
}
}
sort(e.begin(), e.end(), [&](auto& left, auto& right) {
return left[2] < right[2];
});
int comp = n;
int total = 0;
for(int i = 0; i < e.size(); i++) {
if(comp == 1) {
break;
}
int v1 = ind[e[i][0]];
int v2 = ind[e[i][1]];
int v3 = e[i][2];
int r1 = findroot(v1);
int r2 = findroot(v2);
if(r1 == r2) {
continue;
}
total += v3;
if(siz[r1] <= siz[r2]) {
dsu[r1] = r2;
siz[r2] += r1;
} else {
dsu[r2] = r1;
siz[r1] += r2;
}
}
cout << total << endl;
return 0;
}
