n,k = gets.split.map &:to_i
p = gets.split.map &:to_i

max = n - k + 1

p_count = 0
del = 0

count = 1
t_p = p[0]
start_i = 0
a = []

(1...p.size).each{ |i|
	if p[i] > t_p then
		count += 1
	else
		if a.size == 0 || (a.size > 0 && a[-1][1] != i - 2) then
			a << [start_i, i - 1]
		end
		if count >= k then
			p_count += 1
			del += count - k
		end
		count = 1
		start_i = i
	end

	t_p = p[i]
}

a << [start_i, p.size - 1]
if count >= k then
	p_count += 1
	del += count - k
end

#print a, del, p_count, "\n"

a.each_cons(2){ |x|
	lx = x[0]
	rx = x[1]
	lx_len = lx[1] - lx[0] + 1
	rx_len = rx[1] - rx[0] + 1
	diff = rx[0] - lx[1] + 1
	
#	print [lx, rx, lx_len, rx_len, diff], "\n"
	
	if
		diff < k &&
		lx_len + diff + rx_len - 1 >= k &&
		p[lx[1] - 1] < p[rx[0]] &&
		p[rx[0] + 1] > p[lx[1]]
	then
#		print [k-diff, rx_len, lx_len], "\n"
		del += [k-diff, rx_len - 1, lx_len - 1].min 
	end
}

puts max - [p_count - 1, 0].max - del