#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;
using i64 = long long;

int main(void) {
  int n; i64 x; scanf("%d%lld", &n, &x);
  vector<i64> a(n);
  for(int i=0; i<n; ++i) { scanf("%lld", &a[i]); }
  sort(begin(a), end(a));
  i64 res = 0;
  for(int i=0; i<n; ++i) {
    i64 y = x - a[i];
    res += upper_bound(begin(a), end(a), y)
         - lower_bound(begin(a), end(a), y);
  }
  printf("%lld\n", res);
  return 0;
}