b=input()
n=input()
c=sorted([input()for i in[0]*n])
a=0
while len(set(c))>2:
	c=sorted(c)
	a+=c[-1]-c[-2]
	b+=c[-1]-c[-2]
	c[-1]-=c[-2]
	if c[1]-c[0]<=b:
		a+=c[1]-c[0]
		b-=c[1]-c[0]
		c[0]+=c[1]-c[0]
#print c
#print b,a
if len(set(c))==2:
	l=c.count(min(c))
	h=c.count(max(c))
	if l<=b and l<h:
		print a+l
	else:
		print a+h
else:
	print a