// http://infoarena.ro/problema/transport
#include <fstream>
#include <vector>
using namespace std;

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

int numberOfTransports;
vector<int> volume;

int transports(int size);
int search(int left,int right);

int main() {
    int lenght,currentNumber;
    int maxim = 0;
    int sum = 0;

    in >> lenght >> numberOfTransports;

    for(int i=1;i<=lenght;i++) {
        in >> currentNumber;
        sum = sum + currentNumber;

        volume.push_back(currentNumber);

        if(maxim < currentNumber)
            maxim = currentNumber;
    }

    out << search(maxim,sum);

    return (0);
}

int search(int left,int right) {
    int middle = (left + right) / 2;
    int answer = transports(middle);

    if(answer == numberOfTransports)
        return middle;
    else
        if(answer < numberOfTransports)
            return search(left,middle);
        else
            return search(middle+1,right);
}

int transports(int size) {
    vector<int>::iterator it;
    int number = 0;
    int current = 0;

    for(it=volume.begin();it!=volume.end();it++)
        if(current + *it <= size)
            current = current + *it;
        else {
            current = 0;
            number++;
        }

    if(current)
        number++;

    return number;
}