#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl "\n"
#define fast ios::sync_with_stdio(NULL); cin.tie(0); cout.tie(0);
#define pb push_back
#define yes cout<<"YES"<<endl
#define no cout<<"NO"<<endl
#define F first
#define S second
#define C continue
#define R return
const ll N=5e5+9;
const ll mod=1e9+7;
const ll oo=1e18;
const ll M=1e6+10;
ll T,n,a[N],x,ans;
int main()
{
    fast
    //freopen("input.in","r",stdin) ;
    //freopen("output.txt","w",stdout);
    T=1;
    //cin>>T;
    while(T--)
    {
        cin>>n;
        for(int i=1;i<=n;i++){
            cin>>a[i];
        }
        sort(a+1,a+n+1);
        x=a[(n+1)/2];
        ans=0;
        for(int i=1;i<=n;i++){
            ans+=abs(a[i]-x);
        }
        cout<<ans;
    }
    return 0;
}
 
/*
 
 
*/