#include<iostream>
#include<algorithm>

using namespace std;

int main(){
    int n,x;
    cin >> n >> x;
    int a[n];
    for(int i=0;i < n;i++){
        cin >> a[i];
    }
    
    int c[n];
    
    for(int i=0;i < n;i++){
        c[i] = x - a[i];
    }
    
    sort(c,c+n);
    
    int ans = 0;
    
    for(int i=0;i < n;i++){
        if(binary_search(c,c+n,a[i])) ans++;
    }
    cout << ans << endl;
    return 0;
}