#include <bits/stdc++.h>

using namespace std;
using i64 = long long;

const int N = 1e5 + 10;

int n, m;
int a[N], cnt[4];

void solve()
{
    cin >> n >> m;
    int ans = 0;
    vector<int> vec;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
        if (a[i] == 1)
            ans += 3;
    }

    a[0] = a[n], a[n + 1] = a[1];

    for (int i = 1; i <= n; i++)
    {
        int t = !a[i] + !a[i - 1] + !a[i + 1];
        vec.push_back(t);
    }

    sort(vec.begin(), vec.end(), greater<>());

    m = n - m;
    for (int i = 0; i < m; i++)
        ans += vec[i];

    cout << ans << '\n';
}

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

    solve();

    return 0;
}