#include<bits/stdc++.h>
using namespace std;
#define int long long
#define INF 0x3f3f3f3f3f3f3f3f
#define pii pair<int,int>
#define fi first
#define se second
#define all(_a) _a.begin(), _a.end()

void solve(){
    int n,m;
    cin>>n>>m;  
    vector<int>a(n);
    int res=3*n;
    for(int i=0;i<n;i++)cin>>a[i];
    priority_queue<int,vector<int>,greater<int>>q;
    for(int i=0;i<n;i++){
        int res=0;
        if(!a[i])res++;
        if(!a[(i+1)%n])res++;
        if(!a[(i-1+n)%n])res++;
        q.push(res);
    }
;
    while(m--){
        res-=q.top();
        q.pop();
    }
    
    cout<<res<<endl;
}
signed main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr), cout.tie(nullptr);
    cout << setiosflags(ios::fixed) << setprecision(15);
    int T;
    T=1;
    //cin>>T;
    while(T--)solve();
    return 0;
}