#include <fstream>

using namespace std;
const int NMAX=16000;
int v[NMAX+5];
ifstream fin("transport.in");
ofstream fout("transport.out");
int n,k;

bool ok(int cap)
{
    int tr,sc,i;
    sc=tr=0;
    for(i=1;i<=n;i++)
    {
        if(v[i]>cap)
            return 0;
        if(sc+v[i]<cap)
        sc=sc+v[i];
        else
        {
            tr++;
            sc=v[i];

        }
    }
    if(sc>0)
        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;
}