#include <iostream>
#include <fstream>

using namespace std;
int v[16000];
ifstream f("transport.in");
ofstream g("transport.out");
int nr_drumuri(int n,int c)
{
    int drum=0,i=1;
    long s=0;
    while(i<n)
    {
        s=0;
        while(s<=c && i<=n)
               s=s+v[i++];
        drum++;
        i--;
    }
    return drum;
}

int main()
{
    int n,k,i,cmin=1;
    long long cmax=0,c,s,st,dr,m,min;
    f>>n;
    f>>k;
    cout<<endl;
    for(i=1;i<=n;i++)
        f>>v[i];
    for(i=1;i<=n;i++)
    {
         cmax+=v[i];
         if(v[i]>cmin)
              cmin=v[i];
    }
    st=cmin;
    dr=cmax;
    while (st!=dr)
    {
        m=(st+dr)/2;
        if(nr_drumuri(n,m)==k)
               c=m;
        if(nr_drumuri(n,m)<k)
               dr=m;
        else
               st=m+1;
    }
    min=cmin;
    i=1;

    while(i<n)
    {
        s=0;
        while(s<=c && i<=n)
               s=s+v[i++];
        i--;
        s=s-v[i];
        if(s>min)
            min=s;
    }
    g<<min;
    f.close();
    g.close();
  return 0;
}