#include <bits/stdc++.h>
using namespace std;
int getCount(int n,int k,vector<int>arr){
	int i=0;
	int count=0;
	for(int j=0;i<n;i++){
		int diff=arr[j]-arr[i];
		while(diff>k){
			i++;
			diff=arr[j]-arr[i];
		}
		count=count+(j-i+1);
	}
	return count-n;
 
}
 
int main() {
	// your code goes here
	int n;
	cin>>n;
	vector<int>arr(n,0);
	for(int i=0;i<n;i++){
		cin>>arr[i];
	}
	int k;
	cin>>k;
	sort(arr.begin(),arr.end()); //need to sort for j>i
 
	cout<<"Count of pairs with difference<=k:"<<getCount(n,k,arr);
	return 0;
}

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NAoxIDIgMyA0CjIK

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