#include <fstream>

using namespace std;
const int NMAX=16000;
int v[NMAX+5];                     //16005*4B=64020B/1000000=<1MB
int n,k;
ifstream fin("transport.in");
ofstream fout("transport.out");
bool ok(int C)
{
  int i,sc=0,tr=0;
  for(i=1;i<=n;i++)
  {
    if(v[i]>C)
      return 0;
    if(sc+v[i]<=C)
      sc=sc+v[i];
    else
    {
      tr++;
      sc=v[i];
    }
  }
  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;
}