from itertools import product
from heapq import heappop, heappush


# lst内ケーキの選び方すべてにおける嬉しさのリスト
def H(lst):
    ret = []
    for pro in product((0, 1), repeat=len(lst)):
        val = 0
        for el, pr in zip(lst, pro):
            if pr: val += el
        ret.append(val)
    return ret


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

mid = N // 2
A_left, A_right = A[:mid], A[mid:]
C, D = H(A_left), H(A_right)
D.sort(reverse=True)

def f(i, j):
    return C[i] + D[j]


hque = []  # タプル(-f(i,j),i,j)を入れる。
for i in range(len(C)):
    heappush(hque, (-f(i, 0), i, 0))

for _ in range(K - 1):
    m_val, i, j = heappop(hque)
    if j + 1 < len(D):
        heappush(hque, (-f(i, j + 1), i, j + 1))

m_val, i, j = heappop(hque)
ans = -m_val
print(ans)