#include <bits/stdc++.h>

using namespace std;

ifstream fin("transport.in");
ofstream fout("transport.out");

int v[16005], n, k;

bool isOK(long long capacitate)
{
    long long cate = 0;
    for(int i=1; i<=n; i++)
    {
        long long cap = capacitate;

        if(v[i]<=cap)
        {
            cate++;
            while(v[i]<=cap)
            {
                cap -= v[i++];
            }
            i--;
        }
        else if(v[i]>capacitate)
            return false;
        else
            i--;
    }

    if(cate<=k) return true;
    return false;
}

long long cb()
{
    long long st = 1, dr = 160000000, m, last = -1;

    while(st<=dr)
    {
        int m = (st+dr) / 2;
        if( isOK(m) )
        {
            last = m;
            dr = m - 1;
        }
        else
        {
            st = m + 1;
        }
    }

    return last;
}


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

    fout << cb();
}