#include<bits/stdc++.h>

using namespace std;

const int N = 1e5 + 5;

int n, m, ans, maxx = -1;
int a[N];
int l, r, mid;

// 4 2 4 5 1 1  

bool check(int temp){ // 分的段比 m <= 返回 true;否则，返回 false;
    int temp1 = 0, temp2 = 0;
    for (int i = 1; i <= n; i ++){
        if (temp - temp1 >= a[i]){
            temp1 += a[i];
            if (i == n){
                temp2 ++;
            }
        }else{
            temp2 ++;
            temp1 = 0;
            temp1 += a[i];
        }
    }
    if (temp2 <= m){
        return true;
    }else{
        return false;
    }
}

void BinS(){

    l = maxx;
    r = N - 5;

    while (l < r){
        mid = (l + r) / 2;
        if (check(mid)){
            r = mid;
        }else{
            l = mid + 1;
        }
    }

    ans = l;

}

int main(){

    cin >> n >> m;

    for (int i = 1; i <= n; i ++){
        cin >> a[i];
        maxx = max(maxx, a[i]);
    }

    BinS();

    cout << ans;

    system("pause");
    return 0;
}