#include<iostream>
#include<algorithm>

using namespace std;

int main(){
    int b, n;
    cin >> b >> n;

    int A[n];
    for(int i = 0; i < n; i++)  cin >> A[i];
    
    sort(A, A+n);
    int mid = n/2;

    int ans = 0;
    for(int x : A)  ans += abs(x-A[mid]);

    if(n%2 == 0){
        mid--;
        int ans2 = 0;
        for(int x : A)  ans2 += abs(x-A[mid]);
        ans = min(ans, ans2);
    }

    cout << ans << endl;
    return 0;
}