#include <fstream>
using namespace std;
const int NMAX=16000;
int v[NMAX+5];
ifstream fin("transport.in");
ofstream fout("transport.out");
int n,k;
bool ok(int cap)
{
    int tr,sc,i;
    sc=0;
    tr=0;
    for(i=1;i<=n;i++)
    {
        if(v[i]>cap) return 0;
        if(sc+v[i]<=cap)
            sc=sc+v[i];
        else
        {
            tr++;
            sc=v[i];
        }

    }
    if(sc>0)
        tr++;
    return tr<=k;
}
    int bsl(int st,int dr)
    {
        int med,last=-1;
        while(st<=dr)
        {
            med=(st+dr)/2;
            if(ok(med))
            {
                last=med;
                dr=med-1;
            }
            else
                st=med+1;
        }
        return last;
    }


int main()
{
   int i,s;
   fin>>n>>k;
   s=0;
   for(i=1;i<=n;i++)
   {
       fin>>v[i];
       s=s+v[i];
   }
   fout<<bsl(1,s);
   fin.close();
   fout.close();
    return 0;
}