#include <iostream>
using namespace std;
#define MAX 1000000
typedef long long llong;
int n, k;
llong T[MAX];

int check(llong P) {
	int i = 0;
	for (int j = 0;j < k;j++) {
		llong s = 0;
		while (s + T[i] <= P) {
			s += T[i];
			i++;
			if (i == n)return n;
		}
	}
	return i;
}
int solve() {
	llong left = 0;
	llong right = 100000 * 10000;
	llong mid;
	while (right - left > 1) {
		mid = (left + right) / 2;
		int v = check(mid);
		if (v >= n)right = mid;
		else left = mid;
	}
	return right;
}
int main()
{
	cin >> n >> k;
	for (int i = 0;i < n;i++)cin >> T[i];
	llong ans = solve();
	cout << ans << endl;
	return 0;
}

