class Heap
  attr_reader :size

  def initialize
    @size = 0
    @heap = []
  end

  def empty?
    @size.zero?
  end

  def push(val)
    index = size
    @size += 1

    while index > 0
      parent = (index - 1) / 2

      break if @heap[parent] <= val

      @heap[index] = @heap[parent]
      index = parent
    end

    @heap[index] = val
  end

  alias_method :<<, :push

  def pop
    val = @heap.first
    root = @heap[size - 1]
    @size -= 1
    index = 0

    while index * 2 + 1 < @size
      left = 2 * index + 1
      right = left + 1

      if right < size && @heap[right] < @heap[left]
        left = right
      end

      break if @heap[left] >= root

      @heap[index] = @heap[left]
      index = left
    end

    @heap[index] = root
    val
  end

  def top
    @heap.first
  end
end

N, K = gets.split.map(&:to_i)
P = gets.split.map(&:to_i)

list = []
rui = Array.new(N + K + 1, 0)

1.upto(N - 1) do |i|
  if P[i - 1] > P[i]
    s = i + K - 1

    rui[i] += 1
    rui[s] -= 1
    list << i
  end
end

sum = 0
ans = 0

min_heap = Heap.new
max_heap = Heap.new

no_sort = false
gone = Hash.new(false)

N.times do |i|
  sum += rui[i]
  
  min_heap.push(P[i])
  max_heap.push(-P[i])

  next if K - 1 > i

  no_change = false

  if i >= K
    v = P[i - K]
    gone[v] = true

    if -max_heap.top == P[i] && min_heap.top == v
      no_change = true
    end

    while !min_heap.empty? && gone[min_heap.top]
      min_heap.pop
    end

    while !max_heap.empty? && gone[max_heap.top]
      max_heap.pop
    end
  end

  if sum > 0
    ans += 1 unless no_change
  else
    no_sort = true
  end
end

if no_sort
  ans += 1
end

puts ans
