#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int INF = 1e9;
const ll LINF = 1e18;
template<class S,class T> ostream& operator << (ostream& out,const pair<S,T>& o){ out << "(" << o.first << "," << o.second << ")"; return out; }
template<class T> ostream& operator << (ostream& out,const vector<T> V){ for(int i = 0; i < V.size(); i++){ out << V[i]; if(i!=V.size()-1) out << " ";} return out; }
template<class T> ostream& operator << (ostream& out,const vector<vector<T> > Mat){ for(int i = 0; i < Mat.size(); i++) { if(i != 0) out << endl; out << Mat[i];} return out; }
template<class S,class T> ostream& operator << (ostream& out,const map<S,T> mp){ out << "{ "; for(auto it = mp.begin(); it != mp.end(); it++){ out << it->first << ":" << it->second; if(mp.size()-1 != distance(mp.begin(),it)) out << ", "; } out << " }"; return out; }

/*
 <url:https://yukicoder.me/problems/no/324>
 問題文============================================================
 =================================================================
 解説=============================================================
 ================================================================
 */

ll solve(){
    ll res = 0;
    int n,m; cin >> n >> m;
    vector<int> w(n); for(auto& in:w) cin >> in;
    
    res = accumulate(w.begin(), w.end(), 0LL);
    vector<int> flag(n,1);
    for(int i = 0; i < n-m; i++){
        int val = INF;
        int idx = -1;
        for(int j = 0; j < n;j++){
            if(flag[j]){
                int cost = 0;
                if(flag[(j+1)%n]) cost += w[j];
                if(flag[(j-1+n)%n]) cost += w[(j-1+n)%n];
                
                if(val > cost){
                    val = cost;
                    idx = j;
                }
            }
        }
        
        res -= val;
        flag[idx] = 0;
    }
    return res;
}
int main(void) {
    cin.tie(0); ios_base::sync_with_stdio(false);
    cout << solve() << endl;
    return 0;
}