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 = []
count = 0
is_sub_sorted_count = 0
(0..(N-2)).each_with_index do |e, i|
    if i < N-K+1
        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.delete(array[i-1])
            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
    if array[i] <= array[i+1]
        count += 1
        if count >= K - 1
            is_sub_sorted_count += 1
        end
    else
        count = 0
    end
end
if is_sub_sorted_count > 1
    ret = ret - is_sub_sorted_count + 1
end
puts ret
