#include <fstream>

using namespace std;

const int NMAX=16000;

int n,k;

int v[NMAX+5];

ifstream fin ("transport.in");

ofstream fout ("transport.out");

bool ok (int c)
{
    int i,tr,sum;
    tr=sum=0;
    for (i=1;i<=n;i++)
    {
        if (v[i]>c)
        return 0;
        if (sum+v[i]<=c)
            sum=sum+v[i];
        else
        {
            sum=v[i];
            tr++;
        }
    }
    if (sum>0)
        tr++;
    return (tr<=k);
}
int bs1(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 s,i,ans;
    fin>>n>>k;
    s=0;
    for (i=1;i<=n;++i)
    {
        fin>>v[i];
        s=s+v[i];
    }
    ans=bs1(1,s);
    fout<<ans<<"\n";
    fin.close();
    fout.close();
    return 0;
}