#include <iostream>
#include <vector>
#include <cmath>
#include <map>
 
using namespace std;
 
#define FOR(i,a,b) for(int i=a; i<=b; i++)
#define DOWN(i,a,b) for(int i=a; i>=b; i--)
 
typedef long long LL;
typedef map<LL,int>::iterator IT;
 
 
int main()
{
	int n;
	LL B,T=0;
	vector<LL> a;
	map<LL,int> count;
	map<LL,bool> checked;
 
	cin>>n>>B;
 
	a.resize(n+1);
	FOR(i,1,n)
	{
		cin>>a[i];
		T += count[B - a[i]];
		count[a[i]]++;
	}
 
	cout<<T<<endl;
 
	return 0;
}

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