\begin{array}{c} \color{#F5FAFF}{F} \color{#9EC1E9}{u} \color{#7DA6D9}{r} \color{#5C8BCD}{i} \color{#7A9CCF}{n} \color{#8BB0D9}{a} \color{#8BB0D9}{F} \color{#7A9CCF}{o} \color{#5C8BCD}{r} \color{#7DA6D9}{c} \color{#9EC1E9}{a} \color{#F5FAFF}{l} \color{#9EC1E9}{o} \color{#FFFFFF}{s} \end{array}

/** 
    * author: furina focalors 
    * from : A3K59 dhV
    * created: 01.09.2025
**/
#include<bits/stdc++.h>
#define hutao long long
using namespace std;
map<hutao,hutao> m;
int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
    cout.tie(0);
    hutao n,dem=0,k;
    cin>>n>>k;
    for(hutao i=1;i<=n;i++)
    {
        hutao a;
        cin>>a;
        dem+=m[k-a];
        m[a]++;
    }
    cout<<dem;
}