/*
TASK: ots
LANG: C++
*/
//Rumen Hristov Hristov

#include <cstdio>
#include <algorithm>
using namespace std;

int n;
int a[1048576];
int used[1048576];

void read()
{
    scanf ("%d",&n);
    
    int i;
    
    for (i=1;i<=n;i++)
    {
        scanf ("%d",&a[i]);
    }
}

void solve()
{
    int i;
    int ans = 0;
    
    sort ( a + 1 , a + n + 1 );
    
    if ( n > 1 )//??????????
    ans = a[2]-a[1];
    
   // printf ("%d\n",ans);
    
    for (i=3;i<n-1;i++)
    {
        if ( used[i-1] == 0 )
        {
            ans += min ( a[i]-a[i-1] , a[i+1]-a[i] );
            if ( a[i+1]-a[i] <= a[i] - a[i-1] )
            {
                used[i] = 1;
            }
        }
        //printf ("%d\n",ans);    
    }
    
    if ( n > 2 )
    ans += a[n] - a[n-1];
    
    printf ("%d\n",ans);
}

int main()
{
    read();
    solve();
    
    return 0;
}
