lower_bound

// In the name of Allah.
// We're nothing and you're everything.
// Ya Ali!
/*
                  ,     \    /      ,
                 / \    )\__/(     / \
                /   \  (_\  /_)   /   \
           ____/_____\__\@  @/___/_____\____
          |             |\../|              |
          |              \VV/               |
          |        ------___-------         |
          |__________Chuta Dragon___________|
           |    /\ /      \\       \ /\    |
           |  /   V        ))       V   \  |
           |/     `       //        '     \|
           `              V                '
        */

#include<bits/stdc++.h>
using namespace std;
typedef  long long ll;
#define fastread() (ios_base:: sync_with_stdio(false),cin.tie(NULL))
#define fi first
#define se second
#define pb push_back
ll const MOD=1000000007;
///-------------------------------------------------------------------------------------------------///
///                KARMA IS LIKE 69,,, YOU GET WHAT YOU GIVE                                        ///
///-------------------------------------------------------------------------------------------------///



#define eb emplace_back



int main()
{
    fastread();

    ll n,k;

    cin>>n>>k;

    ll cnt=0,ara[n+1];

     for(ll i=0;i<n;i++)
     {

    cin>>ara[i];

     //    if(a<k)cnt++;

     }

     sort(ara,ara+n);

     ll sum=0;

     for(ll i=0;i<n;i++)
     {
         ll a;

         a=k-ara[i];
  //cout<<a<<endl;

        if(a>0) {
             ll  pos=lower_bound(ara,ara+n,a)-ara;
              // cout<<pos<<" pos"<<endl;
        cnt=pos-i-1;
    if(cnt>0)sum+=cnt;
       // cout<<cnt<<endl;
           //  break;


         }


     }

  //  cout<<cnt<<endl;

   //  cout<<(cnt*(cnt+1))/2<<endl;


      cout<<sum<<endl;

}