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

    }
    if(s>0)
        tr++;
    return tr;
}
int bs(int st,int dr)
{
   int med,last=-1;
   while(st<=dr)
   {
       med=(st+dr)/2;
       if(ok(med)<=k)
       {
        last=med;
        dr=med-1;
       }
       else
        st=med+1;
   }
   return last;
}
int main()
{
    int i,s;
    fin>>n>>k;
    for(i=1;i<=n;i++)
    {
        fin>>v[i];
        s=s+v[i];


    }
    fout<<bs(1,s);

    return 0;
}