#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 10;

int b[N];

int main()
{
    ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
    int n, a;
    cin >> n >> a;
    for (int i = 0; i < n; i++)
        cin >> b[i];
    int cnt[4] = {0, 0, 0, 0}, tmp;
    for (int i = 0; i < n; i++)
    {
        tmp = 3 - b[i] - b[(i + 1) % n] - b[(i + n - 1) % n];
        cnt[tmp]++;
    }
    int dec = 0;
    while (a)
    {
        for (int i = 0; i < 4; i++)
        {
            if (cnt[i] != 0)
            {
                a--;
                cnt[i]--;
                dec += i;
                break;
            }
        }
    }
    cout << 3 * n - dec << endl;
    return 0;
}