#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

signed main(){
    ios::sync_with_stdio(false);
	cin.tie(0);
 
    int n;
    cin>>n;
    ll y[n];
    for(int i=0;i<n;i++){
        cin>>y[i];
    }
    ll ans=0;
    sort(y,y+n);
    ll mid=y[n/2];
    for(int i=0;i<n;i++){
        ans+=abs(mid-y[i]);
    }
    cout<<ans<<endl;

}