#include<bits/stdc++.h>
#define int long long
#define deg(a) cout << #a << " = " << a << "\n";
#define de(a) cout << #a << " = " << a << " ";
#define x first
#define y second
using namespace std;
const int N=2e6+10;
pair<int,int> p;
int l[N],r[N],sl[N],sr[N];
int cnt,res;
signed main()
{
    int n,m;
    cin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        int x;
        cin>>x;
        if(x==0)cnt++;
        else if(x<0)l[-x]++;
        else r[x]++;
    }
    for(int i=1;i<N;i++)
    {
        sl[i]=sl[i-1]+l[i];
        sr[i]=sr[i-1]+r[i];
    }
    for(int i=m;i>=0;i--)
    {
        int j=max(0ll,m-2*i);
        res=max(res,cnt+sl[i]+sr[j]);
        res=max(res,cnt+sl[j]+sr[i]);
    }
    cout<<res<<endl;
    return 0;
}