#include <fstream>
#include <algorithm>
using namespace std;
ifstream   in("transport.in");
ofstream out("transport.out");
int n , v[100000] , k , mid , vmin;
int s , nr;
bool verif (int vmin)
{
    int i ;
    int vc=0 , nrtransp=1;
    for (i=1 ; i<=n ; i++)
    {
        if (vc+v[i]<=vmin)
         vc+=v[i];
        if (vc==vmin)
        {
            nrtransp++;
            vc=0;
        }


    }
    return (nrtransp<=k);

}

int cautbin(int l , int r )
{


mid=(l+r)/2;
if ( verif(mid) && !verif(mid-1) )
        if ( v[mid]<vmin )
            return v[mid];
            else return vmin;

if (  verif(mid) )
{
    if (v[mid]<vmin)
    {
            vmin=v[mid];
    return cautbin(l , mid); }
    }

if ( !verif(mid) )
    return cautbin(mid , r);


}

int main()
{

int i ;
in>>n>>k;
for (i=1 ; i<=n ; i++)
{
    in>>nr;
    v[i]=v[i-1]+nr;
}
vmin=v[n];
out<<cautbin(1 , n );
return 0;

}