Problem:
Score : 500 points

Problem Statement

We have N logs of lengths A_1,A_2,\cdots A_N.

We can cut these logs at most K times in total. When a log of length L is cut at a point whose distance from an end of the log is t (0<t<L), it becomes two logs of lengths t and L-t.

Find the shortest possible length of the longest log after at most K cuts, and print it after rounding up to an integer.

Constraints

1 \leq N \leq 2 \times 10^5

0 \leq K \leq 10^9

1 \leq A_i \leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N K
A_1 A_2 \cdots A_N

Output

Print an integer representing the answer.

Sample Input 1

2 3
7 9

Sample Output 1

4

First, we will cut the log of length 7 at a point whose distance from an end of the log is 3.5, resulting in two logs of length 3.5 each.

Next, we will cut the log of length 9 at a point whose distance from an end of the log is 3, resulting in two logs of length 3 and 6.

Lastly, we will cut the log of length 6 at a point whose distance from an end of the log is 3.3, resulting in two logs of length 3.3 and 2.7.

In this case, the longest length of a log will be 3.5, which is the shortest possible result. After rounding up to an integer, the output should be 4.

Sample Input 2

3 0
3 4 5

Sample Output 2

5

Sample Input 3

10 10
158260522 877914575 602436426 24979445 861648772 623690081 433933447 476190629 262703497 211047202

Sample Output 3

292638192

Solution in C++ (GCC 9.2.1) (judge verdict: Accepted)

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define sz(a) int((a).size())

bool ok(ll len, vector<ll>& a, ll k)
{
    ll val = 0;
    for(ll i=0;i<a.size();i++)
    {
        val+=(a[i]/len);
        if(a[i]%len==0) val--;
    }
    return (val<=k);
}

int main()
{
    ios_base::sync_with_stdio(false);
	cin.tie(0);cout.tie(0);
    
    ll i,j,n,k;
    cin>>n>>k;
    vector<ll> a(n);
    for(i=0;i<n;i++) cin>>a[i];
    ll x = 0;
    for(ll z = 1e10; z > 0; z /= 2)
    {
        while(!ok(x+z,a,k)) x+=z;
    }
    cout<<x+1<<"\n";
}