#include<bits/stdc++.h>
using namespace std;
int n, m;
int a[100005];
bool check(long long x) {
	long long ans = 0, cnt = 1;
	for (int i = 1; i <= n; i++) {
		if (a[i] > x)return 0;
		if (ans + a[i] <= x) 
			ans += a[i];
		else {
			ans = a[i];
			cnt++;
		}
	}
	return cnt <= m;
}
int find() {
	int l = 0, r = 1e9+1;
	while (l + 1 < r) {
		long long mid = l + r >> 1;
		if (check(mid))r = mid;
		else l = mid;
	}
	return r;
}
int main() {
	cin>>n>>m;
	for (int i = 1; i <= n; i++)
		cin>>a[i];
	cout << find();
	return 0;
}
}

傻子才会信这是AC代码