#define _USE_MATH_DEFINES #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include typedef long long int ll; //#include using namespace std; ll gcd(ll a, ll b) { if (a < b)swap(a, b); if (b == 0)return a; return gcd(b, a % b); } int lcm(int a, int b) { return a * b / gcd(a, b); } int main() { int Q; Q = 1; //cin >> Q; while (Q--) { int n; cin >> n; int x; cin >> x; vectorp(n); mapmp; for (int i = 0; i < n; i++) { cin >> p[i]; mp[p[i]]++; } ll ans = 0; for (ll i = 0; i <=min(x,100000) ; i++) { if(i+i!=x)ans += mp[i] * mp[abs(x - i)]; else { if(mp[i])ans += mp[i] * mp[i]; } //cout << ans; } cout << ans; } return 0; }