include

include

include

using namespace std; const int N = 100010; int a[N]; int n;

int main(){

scanf("%d",&n);
for(int i=0;i<n;i++) scanf("%d",&a[i]);
sort(a,a+n);
int mid = a[n/2];
int ans = 0;
for(int i=0;i<n;i++) ans += abs(a[i] - mid);
cout << ans;
return 0;

}