#include <stdio.h>
#include <stdlib.h>

int main() {
	long long n, c, sum = 0;
	scanf("%lld %lld", &n, &c);
	
	long long a[n + 1]; 
	int count[2000001] = {0}; 
	
	
	for (long long i = 1; i <= n; i++) {
		scanf("%lld", &a[i]);
		count[a[i]]++; 
	}
	

	for (long long i = 1; i <= n; i++) {
		sum+= count[a[i] + c]; 
	}
	
	printf("%lld\n", sum); 
	return 0;
}
 ```  ```