#include <iostream>
#include <algorithm>
#include <vector>
#include <utility>
#include <set>
using std::cin, std::cout;

#define F(i, a, b) for(int i = a; i <= (b); ++i)
#define F2(i, a, b) for(int i = a; i < (b); ++i)
#define dF(i, a, b) for(int i = a; i >= (b); --i)
#define debug(...) std::fprintf(stderr, __VA_ARGS__)
#define Debug debug("Passing [%s] in LINE %d\n", __FUNCTION__, __LINE__)

void Solve();
int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    Solve();
    return 0;
}

const int MN = 100005;

int n, a;
int b[MN];

void Solve() {
    cin >> n >> a;
    F2(i, 0, n) cin >> b[i], b[i] = !b[i];
    int c[4] = {0, 0, 0, 0};
    F2(i, 0, n)
        ++c[b[i] + b[(i + 1) % n] + b[(i + 2) % n]];
    int ans = 3 * n;
    while (a && c[0]) --a, --c[0];
    while (a && c[1]) --a, --c[1], ans -= 1;
    while (a && c[2]) --a, --c[2], ans -= 2;
    while (a && c[3]) --a, --c[3], ans -= 3;
    cout << ans << '\n';
}