#include<bits/stdc++.h>
using namespace std;
#define REP(i,n) for(int i=0;i<n;i++)
#define ll long long

int main(){
    int b,n;
    ll ave=0,ans=0;
    cin >> b >> n;
    vector<int> c(n);
    REP(i,n) cin >> c[i],ave+=c[i];
    ave/=n;
    REP(i,n) ans+=abs(c[i]-ave);
    cout << ans << endl;
    return 0;
}