#include <cstdio>
#include <algorithm>
using namespace std;
const int MXN = 100000;
int n, m;
int a[MXN];

int check(int m) {
    int t, ans;
    t = 0;
    ans = 1;
    for (int i = 0; i < n; i++) {
        if (t + a[i] <= m)
            t += a[i];
        else {
            t = a[i];
            ans++;
        }
    }
    return ans;
}

int main() {
    freopen("divide_b4.in", "r", stdin);
    freopen("divide_b4.out", "w", stdout);
    scanf("%d%d", &n, &m);
    int l = 0;
    int r = 0;
    for (int i = 0; i < n; i++) {
        scanf("%d", &a[i]);
        r += a[i];
        l = max(l, a[i]);
    }
    while (l < r) {
        int mid = (l + r) / 2;
        if (check(mid) <= m)
            r = mid;
        else
            l = mid + 1;
    }
    printf("%d\n", l);
}