N,K=gets.chomp.split(" ").map(&:to_i)
array = gets.chomp.split(" ").map(&:to_i)

ret = 0
sorted_added = false
pre_min = nil
pre_max = nil
sub = []
(0..N-K).each_with_index do |e, i|
    no_count = false
    if i > 0 && pre_min == array[i-1] && pre_max <= array[i+K-1]
        no_count = true
    end
    if sub.empty?
        sub = array.slice(i..(i+K-1)).sort
    else
        sub.shift
        ins_index = sub.bsearch_index {|x| x >= array[i+K-1] }
        if ins_index
            sub.insert(ins_index, array[i+K-1])
        else
            sub.push(array[i+K-1])
        end
    end
    pre_min = sub[0]
    pre_max = sub[K-1]
    ret += 1 if !no_count
end
count = 0
(0..(N-2)).each_with_index do |e, i|
    if array[i] <= array[i+1]
        count += 1
        if count >= K
            ret -= 1
        end
    else
        count = 0
    end
end
puts ret
