#include <fstream>

using namespace std;
ifstream cin ("transport.in");
ofstream cout ("transport.out");
int v[16001];
int main()
{
    int n,k,i,maxi=-1,smax=0,st,dr,sol,mijl,s,nrt;
    cin>>n>>k;
    for (i=1; i<=n; i++)
    {
        cin>>v[i];
        smax=smax+v[i];
        if (v[i]>maxi)
            maxi=v[i];
    }
    st=maxi;
    dr=smax;
    sol=-1;
    while (st<=dr)
    {
        mijl=(st+dr)/2;
        s=0;
        nrt=1;
        for (i=1; i<=n; i++)
        {
            if (s+v[i]<=mijl)
            {
                s=s+v[i];
            }
            else
            {
                nrt++;
                s=v[i];
            }
        }
        if (nrt>k)
        {
            st=mijl+1;
        }
        else
        {
            sol=mijl;
            dr=mijl-1;
        }
    }
    cout<<sol;
    return 0;
}