#include <iostream>
#include <fstream>
#include <vector>
#include <numeric>
using namespace std;

int check(vector<int>&v, int capacity, int k) {
    int  i = 0;
    while(i < v.size() && k > 0) {
        int ocuppied = 0;
        int last_i = i;
        while(ocuppied < capacity){
            ocuppied += v[i++];
        }
        if (ocuppied > capacity) {
            i--;
        }
        if (last_i == i){
            return 0;
        }
        k--;
    }

    return i >= v.size();
}

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 = 1;
    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;
}