#include <iostream>
#include <algorithm>
#define FOR(i,a,b) for(int i=a;i<b;i++)
using namespace std;

int main(){
    int n; cin>>n;
    int y[100001];
    FOR(i,0,n){
        cin>>y[i];
    }
    sort(y,y+n);
    int mid=y[n/2];
    long int ans=0;
    FOR(i,0,n){
        ans+=abs(mid-y[i]);
    }
    cout<<ans<<endl;
}