/*
TASK: ots
LANG: C++
*/
#include<iostream>
#include<algorithm>
#include<stdlib.h>
using namespace std;
int check[100000];
int main()
{
    unsigned long long int n,a[100000],i,sum=0,min1,tmp,minj,j;
    cin>>n;
    for(i=0;i<n;i++)cin>>a[i];
    
    for(i=0;i<n;i++)
    {
                    if(check[i]==0)
                    {
                                   check[i]=1;
                                   min1=max(a[0],a[i])-min(a[0],a[i]);
                                   minj=0;
                                   for(j=0;j<n;j++)
                                   {
                                          int v=max(a[j],a[i])-min(a[j],a[i]);         
                                          if(v==0)continue;
                                          if(min1>v||min1==0)
                                          {
                                                      min1=v;
                                                      minj=j;
                                          }
                                   }
                                   sum+=min1;
                                   check[minj]=1;
                    }                        
    }
    cout<<sum<<"\n";
    return 0;
}                           
