ac

#include <bits/stdc++.h>
using namespace std;
int main()
{
int n;
int a[100010];
cin>>n;
for (int i=1;i<=n;i++)
cin>>a[i];
sort(a+1,a+1+n);
int mid;
if (n%2==0)
mid=a[n/2];
else
mid=a[(n+1)/2];
int ans=0;
for (int i=1;i<=n;i++){
ans += abs (a[i] - mid);
}
cout << ans;
return 0;
}