You are given a set of points x1x1, x2x2, ..., xnxn on the number line.
Two points ii and jj can be matched with each other if the following conditions hold:
- neither ii nor jj is matched with any other point;
- |xi−xj|≥z|xi−xj|≥z.
What is the maximum number of pairs of points you can match with each other?
Input
The first line contains two integers nn and zz (2≤n≤2⋅1052≤n≤2⋅105, 1≤z≤1091≤z≤109) — the number of points and the constraint on the distance between matched points, respectively.
The second line contains nn integers x1x1, x2x2, ..., xnxn (1≤xi≤1091≤xi≤109).
Output
Print one integer — the maximum number of pairs of points you can match with each other.
Examples
4 2
1 3 3 7
2
5 5
10 9 5 8 7
1
Note
In the first example, you may match point 11 with point 22 (|3−1|≥2|3−1|≥2), and point 33with point 44 (|7−3|≥2|7−3|≥2).
In the second example, you may match point 11 with point 33 (|5−10|≥5|5−10|≥5).
#include <iostream>
#include <algorithm>
#include <cstdio>
#include <string>
#include <cstring>
#include <cstdlib>
#include <map>
#include <vector>
#include <set>
#include <queue>
#include <stack>
#include <cmath>
//
#define lson rt<<1, l, m
#define rson rt<<1|1, m+1, r
//
#define fi first
#define se second
#define pb push_back
#define pq priority_queue<int>
#define ok return 0;
#define os(str) cout<<string(str)<<endl;
#define gcd __gcd
#define mem(s,t) memset(s,t,sizeof(s))
#define debug(a,n) for(int i=0;i<n;i++) cout<<a[i]<<" "; cout<<endl;
#define debug1(a,n) for(int i=1;i<=n;i++) cout<<a[i]<<" "; cout<<endl;
#define debug02(a,n,m) for(int i=0;i<n;i++) {for(int j=0;j<m;j++) cout<<a[i][j]<<" "; cout<<endl; }
#define read11(a,k) for (int i = 1; i <= (int)(k); i++) {cin>>a[i];}
#define read02(a,n,m) for(int i=0;i<n;i++) {for(int j=0;j<m;j++) cin>>a[i][j] ; }
#define TLE std::ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); cout.precision(10);
using namespace std;
inline void NO()
{
cout<<"NO"<<endl;
}
inline void YES()
{
cout<<"YES"<<endl;
}
const int mxn = 2e5+10;
#define oi(x) cout<<x<<endl;
#define rep(k) for (int i=0;i<n;i++)
#define rep1(j,k) for (int i=j;i<=k; i++)
#define per(j,k) for (int i=j;i>=k; i--)
//#define per(k) for (int i=k-1;i>=0;i--)
#define lli long long
string str,ch;
lli a[mxn],vis[mxn];
int n,k,ans;
int judge(int mid)
{
for(int i=n-mid ,j=0; i<n;i++)
{
if(a[i]-a[j]<k)
{
return 0;
}
else
j++;
}
ans = mid;
return 1;
}
int main()
{
while(cin>>n>>k)
{
ans = 0;
for(int i=0;i<n;i++) cin>>a[i];
sort(a,a+n);
int l = 0 ,r = n/2 , mid;
while(l<=r)
{
mid = l + ( (r-l)>>1 );
//cout<<" +++ "<<ans<<endl;
if(judge(mid))
l = mid +1 ;
else
r = mid - 1;
}
cout<<ans<<endl;
}
ok;
}