#include<iostream>

#include<cstdio>

#include<cstring>

#include<queue>

#define maxn 200050

using namespace std;

long long n,val[maxn],ans=,m;

bool vis[maxn];

struct node

{

    long long w,pos;

    friend bool operator < (node x,node y)

    {

        return x.w<y.w;

    }

};

priority_queue <node> q;

int main()

{

    memset(vis,true,sizeof(vis));

    scanf("%lld%lld",&n,&m);

    for (long long i=;i<n;i++)

    {

        scanf("%lld",&val[i]);

        node now;

        now.w=val[i];now.pos=i;

        q.push(now);

    }

    if (m>=(n/)+) {printf("Error!\n");return ;}

    long long cnt=;

    do

    {

        node now=q.top();

        q.pop();

        if (vis[now.pos]==true)

        {

            cnt++;

            long long left=(now.pos-+n)%n,right=(now.pos++n)%n;

            while (vis[left]==false)

                left=(left-+n)%n;

            while (vis[right]==false)

            right=(right++n)%n;

            vis[left]=false;vis[right]=false;

            node then;

            then.w=val[left]+val[right]-val[now.pos];

            then.pos=now.pos;

            q.push(then);

            ans=ans+val[now.pos];

            val[now.pos]=val[left]+val[right]-val[now.pos];

        }

    }while (cnt!=m);

    printf("%lld\n",ans);

    return ;

}