#include<stdio.h>
long x[16005],n,k,s2;
int ok(int c)
{
    int u,s,i,nt=0,l;
    u=1;
    s=0;
    for (i=1;i<=n;i++)
    {
        l=c;
        if (x[i]>c) return k+1;
            else
            {
                if (s+x[i]<=c)
                    s=s+x[i];
                else
                {
                    nt++;
                    s=x[i];
                }
            }
    }
    if (s<c) nt++;
    return nt;
}
int cb()
{
    int st,dr,med,last=-1;
    st=1;
    dr=s2;
    while (st<=dr)
    {
        med=(st+dr)/2;
        if (ok(med)<=k)
        {
            dr=med-1;
            last=med;
        }
        else
            st=med+1;
    }
    return last;
}
int main()
{
    freopen("transport.in","r",stdin);
    freopen("transport.out","w",stdout);
    scanf("%ld%ld",&n,&k);
    int i;
    for (i=1;i<=n;i++)
    {
        scanf("%ld",&x[i]);
        s2=s2+x[i];
    }
    printf("%ld",cb());
}