C++ :

#include<iostream>
#include<algorithm>
using namespace std;
const int N = 10005;
int a[N];

int main(){
	int n,k;
	cin>>n>>k;
	for (int i=1; i<=n; i++) cin>>a[i];
	sort(a+1,a+n+1);
	for (int i=n,x,j; i>=2; i--){
		x=(a[i]+a[i-1])/k;
		j=i-2;
		while (x<a[j]){
			a[j+1]=a[j];
			j--;
		}
		a[j+1]=x;
	}
	cout<<a[1]<<endl;
	return 0;
}