#include<bits/stdc++.h>
using namespace std;
#include<atcoder/convolution>
using namespace atcoder;
typedef long long ll;
int main(){
	ll n,x;cin >> n >> x;
	if(x>1000000){
		cout<<0<<endl;
		return 0;
	}
	vector<ll>cnt(x+1);
	for(;n--;){
		ll a;cin >> a;
		if(a<=x)cnt[a]++;
	}
	auto ret = convolution_ll(cnt,cnt);
	cout << ret[x] << endl;
}