#include <fstream>

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