#include <iostream>
#include <cmath>

#define rep(i,a,b) for(int i=(a);i<(b);i++)
using namespace std;

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

	int *c = new int[n];
	int sum = 0, avg;
	rep(i,0,n) {
		cin >> c[i];
		sum += c[i];
	}
	avg = sum / n;

	int res = 0;
	rep(i,0,n) if(c[i] != avg) res += abs(c[i]-avg);

	cout << res << endl;

	return 0;
}