#include <fstream>
#include <stdlib.h>
using namespace std;
int n,k,v[16000],cs,cd,l2,l;
bool t;
void bin(int cs,int cd);
int main ()
{
    FILE *fin;
    fin=fopen ("transport.in","r");
    fscanf(fin,"%d %d",&n,&k);
    for(int i=0; i<n; ++i)
    {
        fscanf(fin,"%d",&v[i]);
        cd+=v[i];
        cs=max(v[i],cs);
    }
    bin(cs,cd);
}
void bin(int cs, int cd)
{

    FILE *fout;
    fout=fopen ("transport.out","w");
    int s=v[0],drum=1;
    l=(cs+cd)/2;
    for(int i=1; i<n; ++i)
    {
        if(v[i]+s<=l)
        {
            s+=v[i];
            continue;
        }
        else
        {
            drum++;
            s=v[i];
            if(drum>k)
            {
                if(t==1&&l2==1+l)
                {
                    fprintf(fout,"%d",l2);
                    fclose (fout);
                    return;
                }
                l2=l;
                t=0;
                cs=(cs+cd)/2;
                bin(cs,cd);
            }
        }
    }
    if(t==0&&l-l2==1)
    {
        fprintf(fout,"%d",l);
        fclose (fout);
        return;
    }
    t=1;
    l2=l;
    cd=(cd+cs)/2;
    bin(cs,cd);
}