#include <iostream>
#include <cmath>
#include <vector>
#include "stdio.h"
using namespace std;

#define ll long long
const int inf = 0x3f3f3f3f;

int main() {
    #ifdef DEBUG
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
    #endif

    #ifdef  INFOARENA
    freopen("transport.in", "r", stdin);
    freopen("transport.out", "w", stdout);
    #endif  //INFOARENA

    ll n;
    cin >> n;
    ll k;
    cin >> k;

    vector<ll> s(n);
    for(int i=0;i<n;i++) {
        cin >> s[i];
    }

    ll res = 0;

    for(ll step = 1ll << 48; step; step>>=1) {
        ll h = res + step;
        ll cap = k;
        ll truck = 0;
        for(int i=0;i<n;i++) {
            if(s[i] > h) {
                res += step;
                break;
            }

            if(truck + s[i] <= h) {
                truck += s[i];
            } else {
                cap--;
                truck = s[i];
            }

            if(cap == 0) {
                res += step;
                break;
            }
        }
    }

    cout << res+1;

    return 0;
}