#include <bits/stdc++.h>
using namespace std;
int n, m, a[100005];
bool check(int mid)
{
    int cnt = 1, tmp = 0;
    for (int i = 1; i <= n; ++i)
    {
        tmp += a[i];
        if (tmp > mid)
            ++cnt, tmp = a[i];
    }
    return cnt <= m;
}
signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin >> n >> m;
    for (int i = 1; i <= n; ++i)
    {
        cin >> a[i];
    }
    int lft = 0, rgh = INT_MAX, mid;
    while (lft + 1 < rgh)
    {
        mid = lft + rgh >> 1;
        if (!check(mid))
            lft = mid;
        else
            rgh = mid;
    }
    cout << rgh << '\n';
    return 0;
}