#include<bits/stdc++.h>
using namespace std;
using ll = long long;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("Yes")
#define p_no() p("No")

const ll mod = 1e9 + 7;
const ll inf = 1e18;

ll dp[100010];

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    ll N;
    cin >> N;

    vector<ll> A(N);
    FOR(i, 0, N){
        cin >> A.at(i);
    }
    sort(ALL(A));

    dp[0] = inf;
    dp[1] = A[1]-A[0];
    dp[2] = A[2]-A[0];

    FOR(i, 3, N){
        dp[i] = inf;
        
        // k = 2
        dp[i] = dp[i-2] + A[i]-A[i-1];

        // k = 3
        ll a = inf;
        if(i>3){
            a = dp[i-3] + A[i] - A[i-2];
        }
        chmin(dp[i], a);
    }

    p(dp[N-1]);
    
    return 0;
}