N, M = map(int, input().split())
W = list(map(int, input().split()))
inf = 10 ** 18
pre = [[-inf] * 2 for i in range(N + 1)]
pre[0][0] = 0
for i in range(1, N):
    dp = [[-inf] * 2 for i in range(N + 1)]
    for j in range(N + 1):
        dp[j][0] = max(dp[j][0], pre[j][0], pre[j][1])
        if j:
            dp[j][1] = max(dp[j][1], pre[j - 1][1] + W[i - 1], pre[j - 1][0])
    dp, pre = pre, dp
ans = max(pre[M])

pre = [[-inf] * 2 for i in range(N + 1)]
pre[1][1] = 0
for i in range(1, N):
    dp = [[-inf] * 2 for i in range(N + 1)]
    for j in range(N + 1):
        dp[j][0] = max(dp[j][0], pre[j][0], pre[j][1])
        if j:
            dp[j][1] = max(dp[j][1], pre[j - 1][1] + W[i - 1], pre[j - 1][0])
    dp, pre = pre, dp

ans = max(ans, pre[M][0], pre[M][1] + W[-1])
print(ans)