MIN = -10**6
n = m = 3000
def solve(s,dp):
	dp[0][s][s] = 0
	for i in xrange(n-1):
		for j in xrange(max(s,i+m-s-n+1),min(i+s,m)+1):
			for k in xrange(2):
				if dp[i][j][k] == MIN:continue
				dp[i+1][j][0] = max(dp[i+1][j][0],dp[i][j][k])
				dp[i+1][j+1][1] = max(dp[i+1][j+1][1],dp[i][j][k]+w[i]*k)
	return max(dp[n-1][m][0],dp[n-1][m][1]+w[n-1]*s)
n,m = map(int,raw_input().split())
w = map(int,raw_input().split())
if m==0:print 0;quit()
if m==n:print sum(w);quit()
dp = [[[MIN]*2 for i in xrange(m+2)] for i in xrange(n)]
ans = solve(0, dp)
for i in xrange(n):
	for j in xrange(m+2):
		for k in xrange(2):
			dp[i][j][k] = MIN
print max(ans, solve(1,dp))