def chmax(DP,i,v):
    if DP[i] < v: DP[i] = v
def chmin(DP,i,v):
    if DP[i] > v: DP[i] = v

def main():
    INF = 1e18
    N = int(input())
    Y = list(map(int, input().split()))
    Y.sort()

    # 2個グループ作るか 3個グループ作るか
    dp = [INF]*(N + 1)
    dp[0] = 0

    for i in range(N): # 切れ目iにいる
        val = dp[i]
        for j in [2, 3]:
            dsti = i + j
            if dsti > N:
                continue
            #if j == 2:
            #    chmin(dp, dsti, val + (Y[i + 1] - Y[i]))
            #else:
            #    chmin(dp, dsti, val + (Y[i + 2] - Y[i]))
            chmin(dp, dsti, val + (Y[i + j - 1] - Y[i]))
    print(dp[-1])

if __name__ == "__main__":
    main()