N = int(input())
Y = sorted(list(map(int, input().split())))
dp = [float('inf')]*N
dp[1] = abs(Y[0]-Y[1])
if N > 2:
    dp[2] = abs(Y[0]-Y[2])
for i in range(3,N):
    dp[i] = min(dp[i-3]+abs(Y[i]-Y[i-2]),dp[i-2]+abs(Y[i]-Y[i-1]))
print(dp[-1])