n, m = gets.split.map(&:to_i)
(puts 0; exit) if m <= 1
ws = gets.split.map(&:to_i)
memo = Array.new(4){ Array.new(m+1, -Float::INFINITY) }

memo[0][m] = 0
memo[3][m-1] = 0
0.upto(n-2){|i|
	[0,m-i-2].max.upto([m,n-i-2].min){|j|
		memo[0][j] = memo[0][j] > memo[1][j] ? memo[0][j] : memo[1][j]
		memo[1][j] = memo[0][j+1] > memo[1][j+1] + ws[i] ? memo[0][j+1] : memo[1][j+1] + ws[i] if j < m
		memo[2][j] = memo[2][j] > memo[3][j] ? memo[2][j] : memo[3][j]
		memo[3][j] = memo[2][j+1] > memo[3][j+1] + ws[i] ? memo[2][j+1] : memo[3][j+1] + ws[i] if j < m
	}
}

puts [memo[0][0], memo[1][0], memo[2][0], memo[3][0]+ws.last].max