N = int(input())
lsY = [-float('INF')]+list(map(int,input().split()))
lsY.sort()

dp = [[0]*(N+1) for i in range(2)]

for i in range(N):
    dp[1][i+1] = dp[0][i]
    dp[0][i+1] = min(dp[0][i]+lsY[i+1]-lsY[i],dp[1][i]+lsY[i+1]-lsY[i])

print(dp[0][-1])