#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;

}