#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, sum;
    fin>>n>>k;
    sum=0;
    for(i=1; i<=n; ++i)
    {
        fin>>v[i];
        sum=sum+v[i];
    }
    fout<<bs(1, sum)<<"\n";
    return 0;
}