#include <fstream>

using namespace std;

const int nmax=16006;
int v[nmax],k,n;

ifstream in ("transport.in");
ofstream out ("transport.out");

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

}

int bs(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,ans;
    in>>n>>k;
    s=0;
    for(i=1;i<=n;i++)
    {
        in>>v[i];
        s=s+v[i];
    }
    ans=bs(1,s);
    out<<ans;
    return 0;
}