#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int tt;
  cin >> tt;
  while (tt--) {
    int n, l;
    cin >> n >> l;
    int b = (l + 449) / 450;
    vector<P> a(n);
    for (auto& [x, y] : a) cin >> x >> y;
    VI ord(n);
    rep(i, n) ord[i] = i;
    ranges::sort(ord, {}, [&](int i) {
      auto [x, y] = a[i];
      int iy = y / b;
      int ix = iy % 2 ? -x : x;
      return P(iy, ix);
    });
    cout << n << '\n';
    for (int i : ord) {
      auto [x, y] = a[i];
      cout << x << ' ' << y << '\n';
    }
  }
}