#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 cap)
{
    int tr=0,sc=0,i;
    for(i=1;i<=n;i++)
    {
        if(v[i]>cap)
            return 0;
        if(sc+v[i]<=cap)
            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)/2;
        if(ok(med))
        {
              last=med;
              dr=med-1;
        }
        else
            st=med+1;
    }
    return last;
}
int main()
{
    int i,s;
    in>>n>>k;
    for(i=1;i<=n;i++)
    {
        in>>v[i];
        s+=v[i];
    }
    out<<bs_left(1,s);
    return 0;
}