#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;

int main(){
  ll b,n,c;
  cin>>b;
  cin>>n;
  vector<ll> vc;
  ll s,a;
  s=0;
  for(int i=0; i<n; ++i){
    cin>>c;
    vc.push_back(c);
    s+=c;
  }
  a=s/n;
  vector<ll> vd;
  ll m;
  m=n;
  for(int i=0; i<n; ++i){
    ll e;
    e=abs(vc[i]-a);
    vd.push_back(e);
  }
  ll x;
  x=0;
  for(int i=0; i<n; ++i){
    x+=vd[i];
  }
  cout<<x<<endl;
  return 0;
}