#include <fstream>
using namespace std;
int v[16000],n,k;
ifstream cin("transport.in");
ofstream cout("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>0)
            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;
    cin>>n>>k;
    s=0;
    for(i=1;i<=n;i++)
    {
        cin>>v[i];
        s=s+v[i];
    }
    ans=bs(1,s);
    cout<<ans<<"\n";
    return 0;
}