// stiu ca e simpla, doar voiam sa o refac
#include <iostream>
#include <fstream>

#define int long long

using namespace std;

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

const int N = 16000;
int v[N + 1], n, k, maxi = -1, s;

int check(int x){
    int cnt = 1, curr_sum = 0;
    for(int i = 1; i <= n; i++){
        if(curr_sum + v[i] <= x) curr_sum += v[i];
        else curr_sum = v[i], cnt++;
    }
    return cnt;
}

signed main(){
    fin >> n >> k;
    for(int i = 1; i <= n; i++) fin >> v[i], maxi = max(maxi, v[i]), s += v[i];
    int st = maxi, dr = s, ans = -1;
    while(st <= dr){
        int mij = (st + dr) / 2, cnt = check(mij);
        if(cnt <= k) dr = mij - 1, ans = mij;
        else st = mij + 1;
    }
    fout << ans;
    return 0;
}