#include <bits/stdc++.h>

using namespace std;

int main() {
  cin.tie(0)->sync_with_stdio(0);
  for (int tc = (cin >> tc, tc); tc--; ) {
    int n; cin >> n;
    int64_t a, b; cin >> a >> b;
    vector<int64_t> v(2 * n);
    for (auto& x: v) cin >> x;
    sort(v.begin(), v.end());
    array<int, 2> x{-1}, y{0, -1}, z;
    for (int i = 0; i < 2 * n; ++i) {
      z = {-1};
      if (i % 2 && ~y[0] && v[i] - v[y[1]] > a) --y[0], y[1] = i - 1;
      if (i % 2) if (~y[0] && v[i] - v[y[1]] <= a) z = max(z, array{y[0], -1});
      else; else if (~y[0]) z = max(z, array{y[0], i});
      if (~x[0] && v[i] - v[i - 1] <= b) z = max(z, array{x[0] + 1, x[1]});
      x = y, y = z;
    }
    cout << y[0] << '\n';
  }
}