#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");
long n,k,i,q1,mijl,l1,l2,q,max1,a[16001],tr,poz;
int main()
{
    fin>>n>>k;
    for (i=1;i<=n;i++)
        {
            fin>>a[i];
            q=q+a[i];
            if (a[i]>max1)
                max1=a[i];
        }
    l1=max1;
    l2=q;
    while (l1<=l2)
    {
        mijl=(l1+l2)/2;
        q1=0;
        tr=0;
        for (i=1;i<=n;i++)
        {
            if (a[i]+q1<=mijl)
                q1=q1+a[i];
            else
            {
                tr++;
                if (a[i]>mijl)
                {
                    tr++;
                    q1=0;
                }
                else
                    q1=a[i];
            }
        }
        if (a[n]+a[n-1]<=mijl)
            tr++;
        if (tr>k)
            l1=mijl+1;
        else
        {
            poz=mijl;
            l2=mijl-1;
        }
    }
    fout<<poz;
    return 0;
}