#![allow(unused_imports, unused_macros, non_snake_case)]
use std::cmp::{max, min, Ordering};
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};

//{{{ macros missing in 1.15.1
#[macro_use]
mod macros {
    macro_rules! eprint {
        ($($t:tt)*) => {{
            use ::std::io::Write;
            let _ = write!(::std::io::stderr(), $($t)*);
        }};
    }
    macro_rules! eprintln {
        () => { eprintln!(""); };
        ($($t:tt)*) => {{
            use ::std::io::Write;
            let _ = writeln!(::std::io::stderr(), $($t)*);
        }};
    }
    macro_rules! dbg {
        ($val:expr) => {
            match $val {
                tmp => {
                    eprintln!(
                        "[{}:{}] {} = {:#?}",
                        file!(),
                        line!(),
                        stringify!($val),
                        &tmp
                    );
                    tmp
                }
            }
        };
    }
}
//}}}

fn run() {
    let stdin = std::io::stdin();
    let mut sc = Scanner::new(stdin.lock());
    let n: usize = sc.read();
    let k: usize = sc.read();
    let p: Vec<usize> = sc.read_vec(n);
    let mut bs = BTreeSet::new();
    let mut last_inv = None;
    for i in 0..k {
        bs.insert(p[i]);
        if i + 1 < k && p[i] > p[i + 1] {
            last_inv = Some(i);
        }
    }
    let mut sorted = if last_inv.is_none() { 1 } else { 0 };
    let mut answer = 1;
    for i in k..n {
        let b = i - k;
        let e = i;
        let smallest = bs.iter().next().unwrap().clone();
        let largest = bs.iter().rev().next().unwrap().clone();
        if p[i - 1] > p[i] {
            last_inv = Some(i - 1);
        }
        let this_is_sorted = match last_inv {
            Some(idx) if idx > b => false,
            _ => true,
        };
        if (smallest == p[b] && largest < p[e]) || (sorted >= 1 && this_is_sorted) {
        } else {
            answer += 1;
        }
        if this_is_sorted {
            sorted += 1;
        }
        bs.remove(&p[b]);
        bs.insert(p[e]);
    }
    println!("{}", answer);
}

fn main() {
    std::thread::Builder::new()
        .name("run".to_string())
        .stack_size(1024 * 1024 * 1024)
        .spawn(run)
        .unwrap()
        .join()
        .unwrap()
}

//{{{ Scanner
pub struct Scanner<R> {
    reader: R,
}

impl<R> Scanner<R> {
    pub fn new(r: R) -> Scanner<R> {
        Scanner { reader: r }
    }
}

fn is_whitespace(b: u8) -> bool {
    b == b' ' || b == b'\n' || b == b'\r' || b == b'\t'
}

impl<R: std::io::Read> Scanner<R> {
    pub fn read<T: std::str::FromStr>(&mut self) -> T {
        let buf = std::io::Read::bytes(self.reader.by_ref())
            .map(|b| b.expect("Read failed"))
            .skip_while(|&b| is_whitespace(b))
            .take_while(|&b| !is_whitespace(b))
            .collect::<Vec<_>>();
        unsafe { std::str::from_utf8_unchecked(&buf) }
            .parse()
            .ok()
            .expect("Parse error")
    }

    pub fn read_vec<T: std::str::FromStr>(&mut self, n: usize) -> Vec<T> {
        (0..n).map(|_| self.read()).collect()
    }

    pub fn read_chars(&mut self) -> Vec<char> {
        self.read::<String>().chars().collect()
    }
}
//}}}


Measured memory_bytes: 14716