140

#include <bits/stdc++.h>

#define fs first
#define sc second
#define mp make_pair
#define pb emplace_back
#define sz(s) ((int) s.size ())
#define all(s) s.begin (), s.end ()

using namespace std;

typedef long long ll;
typedef pair<int, int> ii;
typedef unsigned long long ull;

const ll linf = (ll) 1e18;

const int pw = 997;
const int N = 100009;
const int M = 10000000;
const int inf = (int) 1e9;
const int mod = (int) 1e9 + 7;

const double eps = 1e-10;
const double pi = 3.1415926535897932384626433832795;

int a[N];

int p[M + 9];
int r[M + 9];

bool e[M + 9];

int get (int v) {
        return v == p[v] ? v : p[v] = get (p[v]);
}
bool unite (int a, int b) {
        a = get (a);
        b = get (b);
        if (a != b) {
                if (r[a] < r[b]) {
                        swap (a, b);
                }
                p[b] = a;
                if (r[a] == r[b]) {
                        r[a]++;
                }
                return 1;
        }
        return 0;
}
inline void prepare () {

}
inline void solve () {
        int n; scanf ("%d", &n);
        int mn = +M;
        int mx = -M;
        for (int i = 0; i < n; i++) {
                scanf ("%d", &a[i]);
                e[a[i]] = 1;
                p[a[i]] = a[i];
                mn = min (mn, a[i]);
                mx = max (mx, a[i]);
        }
        sort (a, a + n);
        n = unique (a, a + n) - a;
        if (n == 1) {
                puts ("0");
                return;
        }
        if (n <= 10000) {
                vector<bool> used (n);
                vector<int> min_e (n, inf), sel_e (n, -1);
                min_e[0] = 0;
                ll ans = 0;
                for (int i = 0; i < n; i++) {
                        int v = -1;
                        for (int j = 0; j < n; j++) {
                                if (!used[j] && (v == -1 || min_e[j] < min_e[v])) {
                                        v = j;
                                }
                        }
                        used[v] = true;
                        ans += min_e[v];
                        for (int to = 0; to < n; to++) {
                                int now = min (a[v] % a[to], a[to] % a[v]);
                                if (now < min_e[to]) {
                                        min_e[to] = now;
                                        sel_e[to] = v;
                                }
                        }
                }
                printf ("%lld", ans);
                return;
        }
        ll ans = 0;
        int cmp = n;
        for (int r = 0; r < mn; r++) {
                for (int i = 0; i < n; i++) {
                        for (int j = a[i]; j <= mx; j += a[i]) {
                                if (e[j + r]) {
                                        bool u = unite (a[i], j + r);
                                        if (u) {
                                                cmp--;
                                                ans += r;
                                                if (cmp == 1) {
                                                        printf ("%lld", ans);
                                                        return;
                                                }
                                        }
                                }
                        }
                }
        }
}
int main () {
        #ifdef FSTREAM
                #define name ""
                freopen (name".in", "r", stdin);
                freopen (name".out", "w", stdout);
        #endif // FSTREAM
        int tests = 1;
        prepare ();
    while (tests--) {
                solve ();
        }
}