#include <fstream>

using namespace std;
ifstream in ("transport.in");
ofstream out ("transport.out");

int v[16000], n, k;

bool verf(int m)
{
    int i=1, j=1, s=0;
    for(i=1; i<=n; i++)
    {
        s=s+v[i];
        if(s>m)
        {
            j++;
            if(j>k)
                return false;
            s=v[i];
        }
    }
    return true;
}

int main()
{
    bool x;
    int cmin=-1, cmax=0, st, dr, mj, i, sol=-1;
    in>>n>>k;
    for(i=1; i<=n; i++)
    {
        in>>v[i];
        if(v[i]>cmin)
        {
            cmin=v[i];
        }
        cmax=cmax+v[i];
    }
    st=cmin;
    dr=cmax;
    if(n<=k)
        out<<cmin;
    else
    {
        while(st<=dr)
        {
            mj=(st+dr)/2;
            x=verf(mj);
            //out<<m<<" "<<x;
            if(x==true)
            {
                dr=mj;
                sol=mj;
            }
            else
            {
                st=mj+1;
            }
        }
    }
    out<<sol;
    return 0;
}