#include <iostream>
#include <algorithm>
#define ll long long
using namespace std;

ll y[100001], dp[100001];
int main(){
	int n; cin>>n;
	ll ans;
	for(int i=0;i<n;i++) cin>>y[i];
	sort(y, y+n);
	if(n==2){
		ans=y[1]-y[0];
	}else if(n==3){
		ans=y[2]-y[0];
	}else{
		dp[0]=1e18;
		dp[1]=y[1]-y[0];
		dp[2]=y[2]-y[0];
		for(int i=3;i<n;i++){
			dp[i]=min(y[i]-y[i-2]+dp[i-3],y[i]-y[i-1]+dp[i-2]);
		}
		ans=dp[n-1];
	}
	cout<<ans<<endl;
	return 0;
}