#include<bits/stdc++.h>
using namespace std;

int n,a[1000],b[100005],k,t,x,maxx=-1,sum;
int main()
{
	cin>>n>>k;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i];
		if(a[i]==0)
		{
			b[i]=b[i-1]+1;
		}
		else
		{
			b[i]=b[i-1];
		}
		
	}
	for(int i=1,j=1;j<=n;)	
	{
		if(b[j]-b[i-1]<=k)
		{
			sum=j-i+1;
			if(sum>maxx)
			{
				maxx=sum;
			}
			j++;
		}
		else
		{
			i++;
		}
	}
	cout<<maxx;
}

#include<bits/stdc++.h>
using namespace std;

int n,a[100005],b[100005],k,t,x,maxx=-1,sum;
int main()
{
	cin>>n>>k;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i];
		if(a[i]==0)
		{
			b[i]=b[i-1]+1;
		}
		else
		{
			b[i]=b[i-1];
		}
		
	}
	for(int i=1,j=1;j<=n;)	
	{
		if(b[j]-b[i-1]<=k)
		{
			sum=j-i+1;
			if(sum>maxx)
			{
				maxx=sum;
			}
			j++;
		}
		else
		{
			i++;
		}
	}
	cout<<maxx;
}