/*
task: ots
lang: C++
*/
#include<iostream.h>
int duljina,k,kuc,i,strat;
long long int a[1000000],n;
int pofka()
{int vodka;
    if(a[i]>a[i+1]) { vodka=a[i];
                      a[i]=a[i+1];
                      a[i+1]=vodka;
                    } 
}
int pomalko(int j)
{
    if((a[j]-kuc)<(a[j+1]-a[j]))duljina+=(a[j+1]-a[j]);
    else duljina+=(a[j]-kuc);
    kuc=a[j+1];
    return j++;
}

int main ()
{
    cin>>n;
    for( i=0;i<n;i++) cin>>a[i];
    if(n%2==0) k=n/2;
    else k=n/2+1;
    for( i=0;i<n;i++) pofka();
    duljina=(a[1]-a[0])+(a[n-1]-a[n-2]);
    kuc=a[1];
    for( i=3;i<=n-2;i++)  for(int j=1;j<=k-2;j+=2) pomalko(j);
    strat=duljina/k;
    if(n==2) cout<<a[1]-a[0];
    else if(strat<0) cout<<-strat;
         else cout<<strat;
    cout<<endl;
return 0;    
}
