n, k = map(int, input().split())
A = sorted(map(int, input().split()))

m = n - k + 1
dp = [0] * m
for i in range(m):
    dp[i] = A[i] - A[0]

for i in range(1, k):
    for j in range(m):
        dp[j] -= A[i+j]
    for j in range(1, m):
        dp[j] = min(dp[j], dp[j-1])
    for j in range(m):
        dp[j] += A[i+j]

print(dp[m-1])