#include<stdio.h>
int main()
{
	long long int b;
	scanf("%lld", &b);
	int n;
	scanf("%d", &n);
	int i, j;
	long long int c[11];
	for (i = 0; i < n; i++)
		scanf("%lld", &c[i]);
	long long int cnt, bb, ans = 1000000000000000;
	for (i = 0; i < n; i++)
	{
		bb = b;
		cnt = 0;
		for (j = 0; j < n; j++)
		{
			if (c[i] < c[j])
			{
				cnt += c[j] - c[i];
				bb += c[j] - c[i];
			}
			else
			{
				cnt += c[i] - c[j];
				bb -= c[i] - c[j];
			}
		}
		if (bb >= 0 && ans > cnt)
			ans = cnt;
	}
	printf("%lld\n", ans);
	return 0;
}