#include "bits/stdc++.h"
using namespace std;
#define fastcin {\
    cin.tie(0);\
    ios::sync_with_stdio(false);\
}
#define rep(i, a, b) for(int i = a; i < b; i++)
#define rrep(i, a, b) for(int i = a; i > b; i--)
#define fore(i, a) for(auto &i:a)
#define print(x) cout << x << "\n"
#define SORT(a, n) sort(a, a+n);
#define REVERSE(a,n) reverse(a,a+n);
#define VSORT(v) sort(v.begin(), v.end());
#define VREVERSE(v) reverse(v.begin(), v.end());
#define MOD 1000000007
typedef long long ll;

int main() {
    fastcin;
    int n;
    cin >> n;
    vector<ll> y(n);
    rep(i, 0, n) cin >> y[i];
    VSORT(y);
    int c = n/2;
    int cn = y[n/2];
    ll ans = 0;
    rep(i, 0, c) {
        ans += (cn - y[i]);
    }
    rep(i, c+1, n) {
        ans += (y[i] - cn);
    }
    print(ans);
    return 0;
}