#include <fstream>

using namespace std;
const int NMAX=16000;
int n,k;
int v[NMAX+5]; ///16005*4B=64020Bytes:1000000<1MB
ifstream in("transport.in");
ofstream out("transport.out");
bool ok(int c)
{
    int i,sc,tr;
    sc=tr=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];
        }
    }
    tr++;
    return tr<=k;
}
int bsleft(int st,int dr)
{
    int mij,last=-1;
    while(st<=dr)
    {
        mij=(st+dr)/2;
        if(ok(mij))
        {
            last=mij;
            dr=mij-1;
        }
        else
            st=mij+1;

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