#include<bits/stdc++.h>
#define ll long long
#define re register
#define INF 2147483647
using namespace std;

inline int read()
{
	int f=1,x=0;char s=getchar();
	while(s<'0'||s>'9')
	{
		if(s=='-') f=-1;
		s=getchar();
	}
	while(s>='0'&&s<='9')
	{
		x=x*10+s-48;
		s=getchar();
	}
	return f*x;
}

const int N=1e6+5;
int a[N],b[N];
vector<int> v[4];
int main()
{
	int n=read(),m=read();
	for(int i=1;i<=n;i++) a[i]=read();
	int ans=0;
	for(int i=1;i<=n;i++)
	{
		int pre=(i+n-2)%n+1;
		int lst=i%n+1;
		int x=a[pre]+a[lst]+a[i];
		v[x].push_back(i);
//		cout<<x<<endl;
	}
	int res=m;
	for(int i=3;i>=0;i--)
	{
		if(res==0) break;
		for(int j=0;j<v[i].size();j++)
		{
			b[v[i][j]]=1;
//			cout<<v[i][j]<<endl;
			res--;
			if(res==0) break;
		}
	}
	for(int i=1;i<=n;i++)
	{
		int pre=(i+n-2)%n+1;
		int lst=i%n+1;
		int x=b[pre]+b[lst]+b[i];
		if(a[i]) ans+=3;
		else ans+=3-x;
	}
	printf("%d\n",ans);
	return 0;
}