#include <cstdlib>
#include <iostream>
#include <stdio.h>

using namespace std;

int n,k,i,j,v[16001],m,s,d,mij,ok,r,minn,rr,ll;

int verif()
{
    int x,l,i,kk,j,ok=1;

    kk=0;
    x=mij;i=1;


    while ((i<=n)&&(ok==1))
    {
    l=0;kk++;j++;
    //if ((l+v[i]>x)or(i>=n)) i++;
    while ((l+v[i]<=x)&&(i<=n))
    {

          l+=v[i];
          i++;
          j=0;
    }
        if (j>=3) ok=0;
    }

    /*if ((kk<=n)&&(kk<minn))
    {
       minn=kk;
       rr=mij;

    }*/

    if ((x<minn)&&(kk<=k)&&(ok==1))
    {
        minn=x;
    }

    if (kk<=k)
    {
        d=mij-1;
    }

    if(kk>k)
    s=mij+1;

    ll=l;
}


int main()
{
    freopen("transport.in","r",stdin);
    freopen("transport.out","w",stdout);

    scanf("%d%d\n",&n,&k);
    minn=k+10;

    for (i=1;i<=n;i++) scanf("%d",&v[i]);
    s=1;d=256000000;

    while (ok==0)
    {

          mij=(s+d)/2;


          verif();

          if (d-s<0)    ok=1;


    }

    printf("%d",minn);
    return 0;
}