#include <iostream>
using namespace std;

const int MAXN = 300010;
int a[MAXN];
int cnt[4];

int main()
{
	ios::sync_with_stdio(false);
	int n, c;
	cin >> n >> c;
	c = n - c;
	for (int i = 0; i < n; i++)
		cin >> a[i];
	for (int i = 0; i < n; i++)
		cnt[a[(i - 1 + n) % n] + a[i] + a[(i + 1) % n]]++;
	int ans = 0;
	for (int i = 0; i <= 3; i++)
	{
		int t = min(c, cnt[i]);
		cnt[i] -= t;
		c -= t;
		ans += t * 3;
	}
	for (int i = 0; i <= 3; i++)
		ans += i * cnt[i];
	cout << ans << '\n';
	return 0;
}