/*
TASK:ots
LANG:C++
*/
#include<iostream>
using namespace std;
int main()
{
  int N,MIN,a[1000],s[1000],p[1000],t,min,p1=1,min1;
   cin>>N;
   for (int i=1;i<=N;i++)
   cin>>a[i];
   for(int y=1;y<=N;y++)
   {min=a[y];
   for(int j=y+1;j<=N;j++)
   {if (a[j]<min)
   {min1=min;
   min=a[j];
    a[j]=min1;}
   
    }
   a[y]=min;
 }
 for (int l=1;l<=N-1;l++)
      {s[l]=a[l+1]-a[l];
 
      }
      for (int t=1;t<=N;t++)
      p[t]=s[t];
      MIN=s[1]+s[N];
      for (int j=2;j<=N-1;j++)
      {if (j%2!=0)  s[j]=1;
      else s[j]=0;}
      for (int r=3;r<=N-1;r=r+2)
      {
      if(s[r-1]==0&&s[r]==1&&s[r+1]==0)
      {if (p[r-1]+p[r+1]<p[r])
      {                              
      s[r-1]=1;
      s[r+1]=1;
      s[r]=0;
      }
      }
      if (s[r]==1&s[r-1]==1&&s[r+1]==0)
      {if(p[r]>p[r+1])
      {s[r]=0;
      s[r+1]=1;}
      }
      if (s[r]==0&&s[r+1]==1&&s[r-1]==1)
      {if (p[r]<p[r+1])
      {s[r]=1;
      s[r+1]=0;}
      }
      }
      for(int g=2;g<=N-1;g++)
      if(s[g]==1)MIN=MIN+p[g];
      cout<<MIN;
      cout<<endl;
      return 0;
      }
      
      
      
      
      
           

   
