import collections
N = int(input())
A = list(map(int,input().split()))
AC = collections.Counter(A)
if len(AC)==1:
    print(1)
    exit()
A.sort()
ME = A[N//2]
FH=[]
SH=[]
for i in range(N):
    if ME>=A[i]:
        FH.append(A[i])
    else:
        SH.append(A[i])
ans = 0
FM = FH[len(FH)//2]
SM = SH[len(SH)//2]
for f in FH:
    ans += abs(f-FM)
for s in SH:
    ans += abs(s-SM)
print(ans)