#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i,m,n) for(int i=m; i<int(n); ++i)
#define repll(i,m,n) for(ll i=m; i<ll(n); ++i)
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define fi first
#define se second

template<typename T> bool chmin(T& a, T b){ if(a > b){a = b; return true;} return false; }
template<typename T> bool chmax(T& a, T b){ if(a < b){a = b; return true;} return false; }

template<typename T> T gcd(T a, T b){ return a % b ? gcd(b, a % b) : b; }
template<typename T> T lcm(T a, T b){ return a / gcd(a, b) * b; }

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N;
    cin >> N;
    vector<ll> Y(N);
    rep(i, 0, N) cin >> Y[i];

    sort(all(Y));
    ll median;
    if(N & 1){
        median = Y[N/2];
    }else{
        median = (Y[N/2] + Y[N/2 - 1])/2LL;
    }

    ll ans = 0LL;
    rep(i, 0, N) ans += abs(Y[i] - median);
    cout << ans << endl;

    return 0;
}