#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <cmath>
using namespace std;
typedef long long LL;
const int N = 1e5 + 10;
int n;
LL res;
int a[N];

int main(){
    scanf("%d",&n);
    for(int i = 0;i < n;++i)    scanf("%d",&a[i]);
    sort(a,a + n);
    for(int i = 0;i < n;++i){
        res += abs(a[i] - a[i >> 1]);
    }
    printf("%lld\n",res);
    return 0;
}