N, K = map(int, input().split())
d = list(map(int, input().split()))
left = [0]
left_m = []
right = [0]
right_m = []
for i, l, r in zip(range(K), d, d[::-1]):
    left.append(left[i] + l)
    left_m.append(l if l < 0 else 0)
    right.append(right[i] + r)
    right_m.append(r if r < 0 else 0)
point = 0
for i in range(K):
    for j in range(K - i):
        p = K - i - j
        minus = list(sorted(left_m[:i] + right_m[:j]))
        point = max(point, left[i] + right[j] - sum(minus[:p]))
print(point)
