N = int(input())
Y = list(map(int, input().split()))
Y.sort()
E = []
N -= 1
for i in range(N):
    E.append(Y[i + 1] - Y[i])
    
inf = 10 ** 18
pre0 = 0
pre1 = inf
for i in range(N):
    dp0 = pre1
    dp1 = min(pre0, pre1) + E[i]
    pre0, dp0 = dp0, pre0
    pre1, dp1 = dp1, pre1
print(pre1)