#include<bits/stdc++.h>
#define int long long
#define ll long long
#define pii pair<int, int>
using namespace std;
const int maxn = 2e5 + 10;
int arr[maxn];
signed main() {
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int n, m; cin >> n >> m;
    for (int i = 0; i < n; i++)
        cin >> arr[i];
    int ans = 3 * n;
    priority_queue<int, vector<int>, greater<int>> q;
    for (int i = 0; i < n; i++) {
        int tem = 0;
        for (int j = -1; j <= 1; j++) {
            int pos = (i + j + n) % n;
            tem += arr[pos] == 0;
        }
        q.push(tem);
    }
    while (!q.empty() && (m--)) {
        ans -= q.top();
        q.pop();
    }
    cout << ans << "\n";
    return 0;
}