#include <fstream>

using namespace std;
const int NMAX=16000; // 16000*4=64000B/10^-6 <mb
int v[NMAX+5];
int n,k;
fstream fin("transport.in");
ofstream fout("transport.out");

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

int bsL(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=0;
    fin>>n>>k;
    for(i=1;i<=n;i++)
        {fin>>v[i];s=s+v[i];}
    fout<<bsL(1,s);
    fout.close();
    fin.close();
    return 0;
}