#include <fstream>

using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");
int v[16001];
int main()
{
    int n,k,i,st=-1,dr=0,mij=0,sol=-1;
    fin>>n>>k;
    for(i=1;i<=n;i++){
        fin>>v[i];
        if(v[i]>st)
            st=v[i];
        dr+=v[i];
    }
    while(st<dr){
        mij=(st+dr)/2;
        i=1;
        int s=0,kf=1;
        for(i=1;i<=n;i++){
            if(s+v[i]>mij){
                s=v[i];
                kf++;
            }
            else
                s+=v[i];
        }
        if(kf<=k){
            dr=mij;
            sol=mij;
        }
        else{
            st=mij+1;
        }
    }
    fout<<sol;
    return 0;
}