#include <bits/stdc++.h>
#define whlie while
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define rep(i,N) for(int i = 0; i < (N); i++)
#define repr(i,N) for(int i = (N) - 1; i >= 0; i--)
#define rep1(i,N) for(int i = 1; i <= (N) ; i++)
#define repr1(i,N) for(int i = (N) ; i > 0 ; i--)
#define each(x,v) for(auto& x : v)
#define all(v) (v).begin(),(v).end()
#define sz(v) ((int)(v).size())
#define vrep(v,it) for(auto it = v.begin(); it != v.end(); it++)
#define vrepr(v,it) for(auto it = v.rbegin(); it != v.rend(); it++)
#define ini(...) int __VA_ARGS__; in(__VA_ARGS__)
#define inl(...) ll __VA_ARGS__; in(__VA_ARGS__)
#define ins(...) string __VA_ARGS__; in(__VA_ARGS__)
using namespace std; void solve();
using ll = long long; using vl = vector<ll>;
using vi = vector<int>; using vvi = vector< vector<int> >;
constexpr int inf = 1001001001;
constexpr ll infLL = (1LL << 61) - 1;
struct IoSetupNya {IoSetupNya() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); cerr << fixed << setprecision(7);} } iosetupnya;
template<typename T, typename U> inline bool amin(T &x, U y) { return (y < x) ? (x = y, true) : false; }
template<typename T, typename U> inline bool amax(T &x, U y) { return (x < y) ? (x = y, true) : false; }
template<typename T, typename U> ostream& operator <<(ostream& os, const pair<T, U> &p) { os << p.first << " " << p.second; return os; }
template<typename T, typename U> istream& operator >>(istream& is, pair<T, U> &p) { is >> p.first >> p.second; return is; }
template<typename T> ostream& operator <<(ostream& os, const vector<T> &v) { int s = (int)v.size(); rep(i,s) os << (i ? " " : "") << v[i]; return os; }
template<typename T> istream& operator >>(istream& is, vector<T> &v) { for(auto &x : v) is >> x; return is; }
void in(){} template <typename T,class... U> void in(T &t,U &...u){ cin >> t; in(u...);}
void out(){cout << "\n";} template <typename T,class... U> void out(const T &t,const U &...u){ cout << t; if(sizeof...(u)) cout << " "; out(u...);}
template<typename T>void die(T x){out(x); exit(0);}
#ifdef NyaanDebug
  #include "NyaanDebug.h"
  #define trc(...) do { cerr << #__VA_ARGS__ << " = "; dbg_out(__VA_ARGS__);} while(0)
  #define trca(v,...) do { cerr << #v << " = "; array_out(v , __VA_ARGS__ );} while(0)
#else
  #define trc(...)
  #define trca(...)
  int main(){solve();}
#endif
 
using P = pair<ll,ll>; using vp = vector<P>;
constexpr int MOD = /**/ 1000000007; //*/ 998244353;
/////////////////

// BIT

template< typename T >
struct BIT {
  int N; int max_2beki;

  vector< T > data;
  // 初期化 1-indexedでデータを管理する 0で初期化
  BIT(int size){
      N = ++size;
      data.assign(N, 0);
      max_2beki = 1;
      while(max_2beki * 2 <= N) max_2beki *= 2;
  }

  // [0,k](閉区間)の総和 閉区間に注意！
  T sum(int k) {
    if(k < 0) return 0; // k<0のとき0を返す
    T ret = 0;
    for(++k; k > 0; k -= k & -k) ret += data[k];
    return (ret);
  }

  // [l,r](閉区間)の総和
  inline T sum(int l,int r){
    return sum(r) - sum(l-1);
  }

  // 一点取得 更新はできないことに注意
  inline T operator[](int k){
    return sum(k) - sum(k-1);
  }

  // data[k] += x;
  void add(int k, T x) {
    for(++k; k < N; k += k & -k) data[k] += x;
  }

  // imos法 [l,r]にxを加算
  void imos(int l,int r,T x){
    add(l , x); add(r + 1 , -x);
  }

  // lower_bound sum(i)がval以上となる最小のi
  int lower_bound(T w){
    if(w <= 0) return 0;
    int x = 0;
    for(int k = max_2beki; k > 0; k /= 2){
      if(x+k <= N - 1 && data[x + k] < w){
        w -= data[x + k];
        x += k;
      }
    }
    return x;
  }

  // upper_bound sum(i)がvalより大きくなる最小のi
  int upper_bound(T w){
    if(w < 0) return 0;
    int x = 0;
    for(int k = max_2beki; k > 0; k /= 2){
      if(x+k <= N - 1 && data[x + k] <= w){
        w -= data[x + k];
        x += k;
      }
    }
    return x;
  }

};

void solve(){
  ini(N,K);
  vi v(N); in(v);
  BIT<int> bit(N);
  rep(i,N-1){
    if(v[i] > v[i+1]) bit.add(i , 1);
  }
  BIT<int> bit2(N+1);
  int ans = 0;
  for(int i = 0;i<K-1;i++){
    bit2.add(v[i] , 1);
  }
  rep(i,N) trc(i,bit.sum(i,i));
  rep(i,N) trc(i,bit2.sum(i,i));
  int flg = 0;
  rep(i,N){
    trc(i);
    if(i + K > N) break;
    bit2.add(v[i+K-1] , 1);
    rep(i,N) trc(i,bit2.sum(i,i));
    if(bit.sum(i , i+K-2)){
      ans++;
      while(1){
        trc("whlie",i);
        if(i+K>=N) break;
        if(bit2.lower_bound(1)==v[i] &&
          bit2.lower_bound(K)<v[i+K]
        ){
          bit2.add(v[i],-1);
          bit2.add(v[i+K],1);
          i++;
        }
        else break;
      } 
    }
    else flg = 1;
    bit2.add(v[i] , -1);
    
    rep(i,N) trc(i,bit2.sum(i,i));
  }
  out(ans + flg);
  
}

Measured memory_bytes: 2560