#include <iostream>
#include<bits/stdc++.h>
 
using namespace std;
 
int lessthank(vector<int> &nums,int k){
	int i=0;
	int j = nums.size()-1;
	int ans=0;
 
	while(i<j){
		int sum = nums[i]+nums[j];
 
		if(sum<=k){
			ans = ans + (j-i);
			i++;
		}
		j--;
	}
 
	return ans;
 
}
 
int main() {
	// your code goes here
	int n,l,r;
	cin>>n>>l>>r;
	vector<int> nums(n);
	for(int i=0;i<n;i++){
		cin>>nums[i];
	}
 
	sort(nums.begin(),nums.end());
	int fr = lessthank(nums,r);
	int fl = lessthank(nums,l-1);
	cout<<fr-fl<<endl;
 
 
 
	return 0;
}

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NyAzIDYgCjAgMSAyIDMgNCA1IDY=

7 3 6 
0 1 2 3 4 5 6