#include <cstdio>

using namespace std;
int n,v[16005];
int ok(int x,int k)
{
    int i,e=1,s=0;
    for(i=1;i<=n;i++)
    {
        if(v[i]>x) return 0;
        s+=v[i];
        if(s>x)
        {
            s=0;
            e++;
            i--;
        }
    }
    return e<=k;
}
int main()
{
    freopen("transport.in","r",stdin);
    freopen("transport.out","w",stdout);

    int k,i,s=0,st,dr,med,c=-1;
    scanf("%d%d",&n,&k);
    for(i=1;i<=n;i++)
    {
        scanf("%d",&v[i]);
        s+=v[i];
    }
    st=1;dr=s;
    while(st<=dr)
    {
        med=st+(dr-st)/2;
        if(ok(med,k))
        {
            dr=med-1;
            c=med;
        }
        else
            st=med+1;
    }
    printf("%d",c);
    return 0;
}