#include <cstdio>
using namespace std;
int v[16009],n,k;
bool ok(int x)
{
    int i,s=0,tr=1;
    for (i=1;i<=n;i++)
    {
        if (s+v[i]<=x)
            s=s+v[i];
        else
        {
            if (v[i]>x)
                return 0;
            s=v[i];
            tr++;
        }
    }
    if (tr<=k)
        return 1;
    return 0;
}
int bs (int l)
{
    int st,dr,med,last=-1;
    st=1;dr=l;
    while (st<=dr)
    {
        med=st+(dr-st)/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;
    scanf("%d%d",&n,&k);
    for (i=1;i<=n;i++)
    {
        scanf("%d",&v[i]);
        s=s+v[i];
    }
    printf("%d",bs(s));
    return 0;
}