#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
typedef long long LL;
int main(int argc, char* argv[])
{
	int N;
	cin>>N;
	vector<LL> A(N,0);
	LL x;
	int i;
	for (i=0;i<N;i++){
		cin>>x;
		A[i]=x;
	}
	sort(A.begin(),A.end());
	LL P;
	if (N%2==1){
		P=A[N/2];
	}else{
		P=(A[N/2-1]+A[N/2])/2;
	}
	LL aw=0;
	for (i=0;i<N;i++){
		x=A[i]-P;
		if (x<0){
			x=-x;
		}
		aw+=x;
	}
	cout<<aw<<endl;
	return 0;
}