B = int(input())
N = int(input())
l = []

for i in range(N):
    l.append(int(input()))

n_median = 0
n_median1 = 0
s = set(l)
if len(s) % 2 == 0:
    n_median = len(s) // 2 
    n_median1 = n_median - 1
else:
    n_median = (len(s) -1) // 2
ll = list(s)
ll.sort()
ck = ll[n_median]
ck1 = ll[n_median1]

ans = 0
ans1 = 0
for l_i in l:
    ans += abs(l_i - ck)
    ans1 += abs(l_i - ck1)

print(min(ans,ans1))