#include <stdio.h>
#include <iostream>
#include <algorithm>

#define MAXN 100001
int arr[MAXN];

using namespace std;
int i, j, N, M;
bool c(int mid) {
	int cnt = 1, sum = 0;
	for (j = 0; j < N; j++) {
		sum += arr[j];
		if (sum <= mid) continue;
		j--;
		sum = 0;
		if (cnt++ >= M)
			return false;
	}
	return true;
}
int main() {
	int l = 0, r = 1, mid;
	scanf("%d %d", &N, &M);
	for (i = 0; i < N; i++) {
		scanf("%d", &arr[i]);
		r += arr[i];
		l = max(l, arr[i]);
	}
	l -= 1;
	
	while (l < r - 1) {
		mid = (l + r) / 2;
		if (c(mid))
			r = mid;
		else
			l = mid;
	}
	printf("%d\n", r);
	return 0;
}