/*
TASK: ots
LANG: C++
*/
#include<iostream>
#include<algorithm>
#include<stdlib.h>
using namespace std;
int main()
{
    unsigned long long int n,a[100000],i,sum=0,min,tmp,mini,j;
    cin>>n;
    for(i=0;i<n;i++)cin>>a[i];
    
    for(i=0;i<n;i++)
    {
                    min=a[i];
                    mini=i;
                    for(j=i+1;j<n;j++)
                    {
                                    if(min>a[j])
                                    {
                                                min=a[j];
                                                mini=j;
                                    }
                    }
                    tmp=a[i];
                    a[i]=min;
                    a[mini]=tmp;
    }
    sum+=a[1]-a[0];
    for(i=2;i<n;i++)
    {
                    if(a[i]-a[i-1]>a[i+1]-a[i])
                    {
                                               sum+=a[i+1]-a[i];
                                               i++;
                    }
                    else sum+=a[i]-a[i-1];
    }
    
    cout<<sum<<"\n";
    FILE *out;
    out=fopen("out.out","w");
    fprintf(out,"%d",sum);
    return 0;
}
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
