#include <iostream>
#include <cstdio>
using namespace std;
int n,m;
int i,j,k;
int x=0,y=0;
int ans=0;
int orz[2600]={0};
int c[2600][2600]={0};
int ab(int a)
{
	if(a<0) return -a;
	else return a;
}
int main()
{
	freopen("orz.in","r",stdin);
	freopen("orz.out","w",stdout);
	cin>>n>>m;
	for(i=0;i<n;i++)
	{
		cin>>orz[i];
		if(orz[i]==1) x++;
		if(orz[i]==2) y++;
	}
	if(m>n||ab(x-y)<=m) cout<<"1";
	else
	{
		for(i=0;i<n;i++)
		{
			for(j=i+1;j<n;j++)
			{
				x=0;y=0;
				for(k=i;k<j;k++)
				{
					if(orz[k]==1) x++;
					if(orz[k]==2) y++;
				}
				c[i][j]=ab(x-y);
				if(c[i][j]>m) ans++;
			}
		}
	}
	cout<<ans;
	return 0;
}