#include <bits/stdc++.h>

using i64 = long long;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int n, z;
    std::cin >> n >> z;
    std::vector<int> a(n, 0);
    int answer = 0;
    for (int i = 0; i < n; i++) {
        int x;
        std::cin >> x;
        if (x == 1) {
            answer += 3;
        } else {
            a[i]++;
            a[(i + 1) % n]++;
            a[(i + 2) % n]++;
        }
    }
    std::sort(a.begin(), a.end());
    for (int i = z; i < n; i++) {
        answer += a[i];
    }
    std::cout << answer << "\n";
    return 0;
}