N = int(input())
Y = list(map(int,input().split()))
Y.sort()
dp0 = 10**10
dp1 = 0
last = Y[0]
for i in range(1,N):
    temp = dp0
    dp0 = min(dp1 + abs(Y[i]-last),dp0 + abs(Y[i]-last))
    dp1 = temp
    last = Y[i]
print(dp0)