import sys

sys.setrecursionlimit(100000)

N, K = map(int, input().split())

p = list(map(int, input().split()))

pre = [0] * (N + 1)

wpre = [0] * (N + 1)

for i in range(1, N + 1):

pre[i] = pre[i - 1] + p[i - 1]

wpre[i] = wpre[i - 1] + p[i - 1] *(i - 1)

ans = 0

def calc(s, t, dep):

global ans

if t - s + 1 < 3 or dep > K:

return

W = pre[t + 1] - pre[s]

Wi = wpre[t + 1] - wpre[s]

best, val = -1, float('inf')

for m in range(s + 1, t):

d = abs(Wi - m * W)

if d < val or (d == val and m < best):

best, val = m, d

ans += p[best]

calc(s, best - 1, dep + 1)

calc(best + 1, t, dep + 1)

calc(0, N - 1, 1)

print(ans)