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

void chmin(int64_t& a, int64_t b){
    a = min(a, b);
}

int main(){
    int N;
    int64_t A[100000];
    cin >> N;
    for(int i=0; i<N; i++) cin >> A[i];
    sort(A, A+N);

    int64_t dp[100001] = {0};
    for(int i=1; i<=N; i++) dp[i] = 1e18;

    for(int i=0; i<N-1; i++){
        chmin(dp[i+2], dp[i] + A[i+1] - A[i]);
        if(i+3 <= N) chmin(dp[i+3], dp[i] + A[i+2] - A[i]);
    }
    cout << dp[N] << endl;
    return 0;
}