#include<stdio.h>

#include<string.h>

#include<iostream>

#include<algorithm>

using namespace std;

const int maxn=1e5+10;

const int INF=0x3f3f3f3f;

#define rt root

#define ls root<<1

#define rs (root<<1)|1

#define mem(a) memset(a,0,sizeof(a))

#define mem_(a) memset(a,-1,sizeof(a))

#define mem__(a) memset(a,INF,sizeof(a))

typedef long long ll;

int tree[maxn<<2],arr[maxn],len[maxn];

int n,d;

struct shudui

{

    int val,id;

} m[maxn];

bool mmp(shudui x,shudui y)

{

    if(x.val!=y.val)

        return x.val<y.val;

    return x.id>y.id;

}

void push_up(int root)

{

    tree[rt]=max(tree[ls],tree[rs]);

}

void update(int root,int L,int R,int pos,int val)

{

    if(L==R)

    {

        tree[rt]=val;

        return;

    }

    int mid=(L+R)>>1;

    if(pos<=mid) update(ls,L,mid,pos,val);

    else update(rs,mid+1,R,pos,val);

    push_up(rt);

}

int query(int root,int L,int R,int LL,int RR)

{

    if(LL<=L && R<=RR)

    {

        return tree[rt];

    }

    int mid=(L+R)>>1,ans=0;

    if(LL<=mid) ans=max(ans,query(ls,L,mid,LL,RR));

    if(RR>mid) ans=max(ans,query(rs,mid+1,R,LL,RR));

    return ans;

}

int main()

{

    ios::sync_with_stdio(0);

    cin.tie(0);

    int i,j,k,n;

    while(cin>>n>>k)

    {

        mem(tree);

        memset(len,0,sizeof(len));

        int mx=-1;

        for(i=1; i<=n; i++)

        {

            cin>>arr[i];

            if(arr[i]>mx)mx=arr[i];

        }

        mx++;

        int ans=0;

        for(i=1; i<=n; i++)

        {  //这个arr[i-k-1]+1就是为了保证严格上升子序列

            if(i-k-1>0)update(1,1,mx,arr[i-k-1]+1,len[i-k-1]);

            if(arr[i]!=0)len[i]=query(1,1,mx,1,arr[i])+1;//arr[i]==0时查找会出现错误111111111111155t

            else len[i]=1;

            if(len[i]>ans)ans=len[i];

        }

        cout<<ans<<endl;

    }

}

/*

5 0

3 1 5 2 3

len1=1

U 4 1

Q 1 1 1

len2=2

U 2 2

Q 1 5 3

len3=3

*/