#include <fstream>

using namespace std;
const int NMAX=16000;
int n,k;
int v[NMAX+5];
ifstream fin ("transport.in");
ofstream fout ("transport.out");
bool ok (int c)
{
    int i,tr,sum;
    tr=sum=0;
    for(i=1;i<=n;++i)
        if(v[i]>c)
        return 0;
    if(sum+v[i]<=c)
        sum=sum+v[i];
    else
    {
        tr++;
        sum=v[i];
    }
    if(sum>0)
        tr++;
    return(tr<=k);
}
int bsL(int st, int dr)
{
    int med, last=-1;
    while(st<=dr)
    {
        med=(st+dr)/2;
        if(ok(med)) //st
        {
            last=med;
            dr=med-1;
        }
        else
        st=med+1; //dr
    }
    return last;
}
int main()
{
    int s,i,ans;
    fin>>n>>k;
    s=0;
    for(i=1;i<=n;++i)
    {
        fin>>v[i];
        s=s+v[i];
    }
    ans=bsL(1,s);
    fout<<ans<<'\n';
    fin.close();
    fout.close();
    return 0;
}