b=int(input())
n=int(input())
c=[int(input()) for i in range(n)]
c.sort()
if n//2==1:
  t=c[n//2]
else:
  t=(c[n//2-1]+c[n//2])//2
x=sum(c)+b
ans=[]
for i in range(max(t-10**5,0),t+10**5):
  if n*i<=x:
    ct=0
    for j in range(n):
      if c[j]>=i:
        ct+=c[j]-i
    for j in range(n):
      if c[j]<i:
        ct+=i-c[j]
    ans.append(ct)
print(min(ans))