N = int(input())
Y = list(map(int, input().split()))
Y.sort()

if N <= 3:
    print(Y[-1] - Y[0])
    exit()

INF = float('inf')
dp = [0] * (N + 1)
dp[0] = INF
dp[1] = 0
dp[2] = Y[1] - Y[0]
dp[3] = Y[2] - Y[0]

for i, y in enumerate(Y[3:], start=3):
    d2 = dp[i - 2] + y - Y[i - 2]  # xxx o o
    d3 = dp[i - 3] + y - Y[i - 1] + Y[i - 2] - Y[i - 3]  # xxx o o o
    dp[i + 1] = min(d2, d3)

print(dp[-1])