#include <iostream>
#include <fstream>
#include <set>
#include <algorithm>

#if 1
#define pv(x) cout<<#x<<" = "<<x<<"; ";cout.flush()
#define pn cout<<endl
#else
#define pv(x)
#define pn
#endif

using namespace std;
ifstream in("transport.in");
ofstream out("transport.out");

using ll = long long;
using ull = unsigned long long;
using ui = unsigned int;
#define pb push_back
#define mp make_pair
const int NMax = 5e6 + 5;
const int inf = 1e9 + 5;
const int mod = 100003;
using zint = int;

int N,K;
int v[NMax];

int nrTransport(int,int);
// nrTransport(nr,mx) - return-eaza numarul de transporturi necesare pentru
// a muta toate saltelele cu un camion de dimensiune nr;
// daca nr < mx, atunci se return-eaza infinit;

int main() {
    in>>N>>K;

    int sum = 0, mx = 0;
    for (int i=1;i <= N;++i) {
        in>>v[i];
        sum += v[i];
        mx = max(mx,v[i]);
    }

    // se realizeaza o cautare binara pentru a obtine
    // capacitatea maxima care necesita mai mult de K drumuri;
    int pos = 0,pw = 1;
    for (;pw <= sum;pw <<= 1) ;
    pw >>= 1;

    while (pw) {
        if (nrTransport(pos+pw,mx) > K) {
            pos += pw;
        }

        pw >>= 1;
    }

    out<<pos+1<<'\n';

    in.close();out.close();
    return 0;
}

int nrTransport(int val,int mx) {
    if (val < mx) {
        return inf;
    }

    // se incarca in fiecare camion numarul maxim de saltele din cele curente;
    int sum = 0, ans = 0;
    for (int i=1;i <= N;++i) {
        if (sum + v[i] > val) {
            ++ans;
            sum = v[i];
        }
        else {
            sum += v[i];
        }
    }

    if (sum != 0) {
        ++ans;
    }

    return ans;
}