#include<bits/stdc++.h>
#define ll long long
#define eps 2000005
using namespace std;
int n,m;
int a[114514],b[3000010],f[3000010];
int main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        cin>>a[i];
        b[a[i]+eps]++;
    }
    sort(a+1,a+n+1);
    for(int i=a[1]-1;i<=a[n]+1;i++){
        f[i+eps]=f[i+eps-1]+b[i+eps];
    }
    int ans=-1;
    for(int i=0;i<=m;i++){
        //cout<<endl<<i<<" "<<((m-2*i)>0?(2*i-m):0)-2<<endl;
        //cout<<f[i+eps]<<" "<<f[((m-2*i)>0?(2*i-m):0)+eps-2]<<endl;
        ans=max(ans,f[i+eps]-f[((m-2*i)-0?-(m-2*i):0)+eps-2]);
    }
    cout<<ans<<endl;
}