#include <cstdio>

using namespace std;

const int NMAX = 16000;
int v[NMAX + 5];//16005 * 4 = 64020;
int n,k;

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
        {
            sc = v[i];
            tr++;
        }
    }
    tr++;
    return tr <= k;
}
int bs(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()
{
    freopen("transport.in","r",stdin);
    freopen("transport.out","w",stdout);

    int i,s = 0,ok;
    scanf("%d%d",&n,&k);
    for (i = 1;i <= n;i++)
    {
        scanf("%d",&v[i]);
        s = s + v[i];
    }
    ok = bs(1,s);
    printf("%d",ok);

    return 0;
}