#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("transport.in");
ofstream fout("transport.out");
int n,k,v[16001],sum,c,k_original,best;
bool ok(int c)
{
    k=k_original;int ccur=c;
    for(int i=1;i<=n;i++)
    {
        if(v[i]<=ccur)
            ccur=v[i];

        else
        {
            k--;
            if(k<=0) return false;
            ccur=c-v[i];
        }
    }

    return true;
}
int cb(int val)
{
    int st=1;
    int dr=sum;
    int mij=st+(dr-st)/2;

    while(st<=dr)
    {
        mij=st+(dr-st)/2;
        if(ok(mij))
        {
            best=mij;
            dr=mij-1;
        }

        else st=mij+1;
    }

}
int main()
{
    fin>>n>>k_original;

    for(int i=1;i<=k;i++)
    {
        fin>>v[i];
        sum+=v[i];
    }

    fout<<best;

    return 0;
}