#include using namespace std; #define int long long #define rep(i,s,n) for(int i = s;i=(s);i--) #define all(v) (v).begin(),(v).end() #define pb push_back #define fi first #define se second #define chmin(a,b) a=min((a),(b)) #define chmax(a,b) a=max((a),(b)) typedef long long ll; typedef pairpint; typedef vectorvint; typedef vectorvpint; typedef pair P1; typedef pair P2; typedef pair PP; static const ll maxLL = (ll)1 << 62; const ll MOD=1000000007; const ll INF=1e18; int N,X; int a,b,x; int ans=0; signed main() { cin>>N>>X; vint v(N); rep(i,0,N){ cin>>v[i]; } sort(all(v)); rep(i,0,N){ a=lower_bound(all(v),X-v[i])-v.begin(); b=upper_bound(all(v),X-v[i])-v.begin(); ans+=b-a; } cout<