#include <fstream>

using namespace std;
int v[16005];
int main()
{
    ifstream in ("transport.in");
    ofstream out("transport.out");
    int n,k,i,x=1,maxx=0, cnt=0, st, dr, mijl,sol=-1;
    in>>n>>k;
    for (i=1;i<=n;i++) {
       in>>v[i];
       cnt+=v[i];
       maxx=max(v[i],maxx);
    }
    st=maxx;
    dr=cnt;
    while (st<=dr) {
        mijl=(st+dr)/2;
        cnt=0;
        x=1;
        for (i=1;i<=n;i++) {
            if (cnt+v[i]<=mijl) {
                cnt+=v[i];
            }else{
            x++;
            cnt=v[i];
            }
        }
        if (x>k) {
            st=mijl+1;
        }else{
        sol=mijl;
        dr=mijl-1;
        }
    }
    out<<sol;
    return 0;
}