import sys

sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


N = I()
Y = LI()
Y.sort()
Y = [0]+Y

if N <= 4:
    if N == 2:
        print(Y[2]-Y[1])
    elif N == 3:
        print(Y[3]-Y[1])
    else:
        print(Y[4]-Y[3]+Y[2]-Y[1])
    exit()

dp = [0]*(N+1)
dp[2] = Y[2]-Y[1]
dp[3] = Y[3]-Y[1]
dp[4] = dp[2]+Y[4]-Y[3]
for i in range(5,N+1):
    dp[i] = min(dp[i-2]+Y[i]-Y[i-1],dp[i-3]+Y[i]-Y[i-2])

print(dp[-1])