#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;      
int a[2500],b,c,d,l,m,s=0;
int ab(int x)
{
	return x>0?x:0-x;
}
int main(void)      
{         
    freopen("orz.in","r",stdin);      
    freopen("orz.out","w",stdout);       
	cin>>b>>c;
	l=0;
	m=0;
	for (d=0;d<b;d++) scanf("%d",&a[d]);
	for (d=0;d<b;d++)
	{
		if (a[d]==1) l++;
			else m++;
		if ((l!=0)&&(m!=0)) 
		{
			if (ab(l-m)>c)
			{
				s++;
				l=0;
				m=0;
				d--;
			}
		}
		if (d==b-1) s++;
	}
	cout<<s;
    fclose(stdin);
	fclose(stdout);
    return 0;      
}