#include <iostream>
#include <fstream>
#include <vector>
#include <numeric>
#include <bits/stdc++.h>
using namespace std;

int check(vector<int>&v, int capacity, int k) {
    int transports = 1 , curr_sum=0;

    for(int i=0;i<v.size();i++){
        if(curr_sum + v[i] > capacity){
            transports++;
            curr_sum = 0;
        }
        curr_sum+=v[i];
        if(transports > k){
            return 0;
        }
    }

    return 1;
}

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

    int n,k;
    fin>>n>>k;
    vector<int> v(n);
    for (int  i = 0;i < n; i++) {
        fin>>v[i];
    }

    int mx = accumulate(v.begin(), v.end(), 0);
    int mn = *max_element(v.begin(), v.end());
    int last = -1;
    while(mn <= mx) {
        int mid = mn + (mx - mn)/2;
        if (check(v, mid, k)) {
            last = mid;
            mx = mid - 1;
        } else {
            mn = mid + 1;
        }
    }
    fout << last;
}