#include <fstream>

using namespace std;
const int NMAX=1600;
int n,k;
int v[NMAX+5];
ifstream fin("transport.in");
ofstream fout("transport.out");
bool ok(int C)
{
    int i,tr,sum;
    tr=sum=0;
    for(i=1;i<=n;++i)
    {
        if(v[i]>C)
            return 0;
        if(sum+v[i]<=C)
            sum=sum+v[i];
        else
        {
            tr++;
            sum=v[i];
        }
    }
    if(sum>0)
        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 s,i,ans;
    fin>>n>>k;
    s=0;
    for(i=1;i<=n;++i)
    {
        fin>>v[i];
        s=s+v[i];
    }
    ans=bsL(1,s);
    fout<<ans<<"\n";
    return 0;
}