n, m = map(int, input().split())
w = list(map(int, input().split()))

INF = 10 ** 9
dp0 = [[-INF, -INF] for i in range(m+1)]
dp1 = [[-INF, -INF] for i in range(m+1)]

dp0[0][0] = 0
dp1[1][1] = 0

for i in range(n-1):
    ndp0 = [[-INF, -INF] for i in range(m+1)]
    ndp1 = [[-INF, -INF] for i in range(m+1)]

    for j in range(m+1):
        ndp0[j][0] = max(dp0[j][0], dp0[j][1])
        ndp1[j][0] = max(dp1[j][0], dp1[j][1])

    for j in range(m):
        ndp0[j+1][1] = max(ndp0[j+1][1], dp0[j][0], dp0[j][1] + w[i])
        ndp1[j+1][1] = max(ndp1[j+1][1], dp1[j][0], dp1[j][1] + w[i])

    dp0 = [x[:] for x in ndp0]
    dp1 = [x[:] for x in ndp1]

# print(dp0)
# print(dp1)

dp1[-1][1] += w[-1]

print(max(max(dp0[-1]), max(dp1[-1])))