#include <set>

 #include <map>

 #include <cmath>

 #include <ctime>

 #include <queue>

 #include <stack>

 #include <cctype>

 #include <cstdio>

 #include <string>

 #include <vector>

 #include <cstdlib>

 #include <cstring>

 #include <iostream>

 #include <algorithm>

 using namespace std;

 typedef unsigned long long ull;

 typedef long long ll;

 const int inf = 0x3f3f3f3f;

 const double eps = 1e-;

 const int maxn = 1e5+;

 int dp[maxn],seg[maxn<<];        //线段树区间求最值

 int a[maxn];

 void update(int l,int r,int pos,int x,int val)

 {

     if (l == r)

     {

         seg[pos] = val;

         return ;

     }

     int mid = (l + r) >> ;

     if (x <= mid)

         update(l,mid,pos<<,x,val);

     if (x > mid)

         update(mid+,r,pos<<|,x,val);

     seg[pos] = max(seg[pos<<],seg[pos<<|]);

 }

 int query(int l,int r,int pos,int x,int y)

 {

     if (x <= l && y >= r)

         return seg[pos];

     int mid = (l + r) >> ;

     int ans1 = ,ans2 = ;

     if (x <= mid)

         ans1 = query(l,mid,pos<<,x,y);

     if (y > mid)

         ans2 = query(mid+,r,pos<<|,x,y);

     return max(ans1,ans2);

 }

 int main(void)

 {

     #ifndef ONLINE_JUDGE

         freopen("in.txt","r",stdin);

     #endif

     int n,d;

     while (~scanf ("%d%d",&n,&d))

     {

         memset(seg,,sizeof(seg));

         int len = ;

         for (int i = ; i < n; i++)

         {

             scanf ("%d",a+i);

             a[i] += ;                     //因为a[i]可能为0，而我的线段树是从1开始的所以加2

             len = max(len,a[i]);

         }

         int ans = ;

         for (int i = ; i < n; i++)

         {

             dp[i] = query(,len,,,a[i]-) + ;   //不能等于，所以减1，dp[i]表示以a[i]结尾的最长不降序列长度，

             if (i >= d)                            //延迟更新，这是这道题的关键，

                 update(,len,,a[i-d],dp[i-d]);

             ans = max(dp[i],ans);

         }

         printf("%d\n",ans);

     }

     return ;

 }