#include <fstream>
using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");
const int NMAX=16000;
int v[NMAX+5];
int n,k;
bool ok(int c)
{
    int tr,i,sc;
    tr=sc=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];
        }
    }
        if(sc>0)
            tr++;
        return tr<=k;
    }
    int bs_left(int st,int dr)
    {
        int med,last=-1;
        while(st<=dr)
        {
            med=st+(dr-st)/2;
            if(ok(med))
            {
                last=med;
                dr=med-1;
            }
            else
                st=med+1;
        }
        return last;
    }
    int main()
    {
        int i,smax;
        smax=0;
        fin>>n>>k;
        for(i=1;i<=n;i++)
        {
            fin>>v[i];
            smax=smax+v[i];
        }
        fout<<bs_left(1,smax);
        fin.close();fout.close();
        return 0;
    }