#include <fstream>

using namespace std;

ifstream cin("transport.in");
ofstream cout("transport.out");
int v[16001];
int main()
{
    int n,k,i,st,dr,mijl,sol,nrt,s;
    cin>>n>>k;
    st=0;
    dr=0;
    for(i=1;i<=n;i++)
    {
        cin>>v[i];
        if(st<v[i])
            st=v[i];
        dr+=v[i];
    }
    sol=-1;
    while(st<=dr)
    {
        mijl=(st+dr)/2;
        /// calculez nr de transporturi in cazul in care camionul are capacitatea mijl
        nrt=1;
        s=0;
        for(i=1;i<=n;i++)
            if(s+v[i]<=mijl)
                s+=v[i];
            else
            {
                s=v[i];
                nrt++;
            }
         if(nrt<=k)
         {
             sol=mijl;
             dr=mijl-1;
         }
         else
            st=mijl+1;
    }
    cout<<sol;
    return 0;
}