#include<fstream>
using namespace std;

ifstream in("transport.in");
ofstream out("transport.out");
const int NMAX=16000;
int v[NMAX+5];
int n,k;

bool ok(int c)
{
    int tr,i,sc;
    tr=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>0)
            tr++;
        return tr<=k;
}

int bs_left(int st, int dr)
{
    int med,last=-1;
    while(st<=dr)
    {
        med=st+(dr-st)/2;
        if(ok(med))
        {
            last=med;
            dr=med-1;
        }
        else st=med+1;
    }
    return last;
}

int main()
{
    int i, smax;
    smax=0;
    in>>n>>k;
    for(i=1;i<=n;i++)
    {
        in>>v[i];
        smax=smax+v[i];
    }
    out<<bs_left(1,smax);
    in.close();
    out.close();
    return 0;
}