#include <fstream>

using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");
const int N=16003;
int a[N];
long long  n,k,sum;
bool ok(int c)
{
    int tr=0,s=0;
    for(int i=1; i<=n; ++i)
    {
        s+=a[i];
        if(s>c)
            ++tr,s=a[i];
    }
    if(s)
        ++tr;
    if(tr<=k)
        return 1;
    else
        return 0;
}
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()
{
    fin>>n>>k;
    for(int i=1; i<=n; ++i)
        fin>>a[i],sum+=a[i];
    fout<<bsL(1,sum);

}