HDU 6759

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <cctype>

#include <algorithm>
#include <random>
#include <bitset>
#include <queue>
#include <functional>
#include <set>
#include <map>
#include <vector>
#include <chrono>
#include <iostream>
#include <limits>
#include <numeric>

#define LOG(FMT...) fprintf(stderr, FMT)

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

// mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

template<class T>
istream &operator>>(istream &is, vector<T> &v) {
  for (T &x : v)
    is >> x;
  return is;
}

template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  if (!v.empty()) {
    os << v.front();
    for (int i = 1; i < v.size(); ++i)
      os << ' ' << v[i];
  }
  return os;
}

typedef pair<ll, ll> pii;

#define x first
#define y second

pii operator+(const pii &lhs, const pii &rhs) { return pii(lhs.x + rhs.x, lhs.y + rhs.y); }

pii operator-(const pii &lhs, const pii &rhs) { return pii(lhs.x - rhs.x, lhs.y - rhs.y); }

ll operator^(const pii &lhs, const pii &rhs) { return lhs.x * rhs.x + lhs.y * rhs.y; }

ll operator*(const pii &lhs, const pii &rhs) { return lhs.x * rhs.y - lhs.y * rhs.x; }

int main() {
#ifdef ELEGIA
  freopen("test.in", "r", stdin);
  int nol_cl = clock();
#endif
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  int T;
  cin >> T;
  while (T--) {
    int n;
    cin >> n;
    vector<pii> t(n);
    for (int i = 0; i < n; ++i)
      cin >> t[i].x >> t[i].y;
    sort(t.begin(), t.end());
    vector<pii> stk;
    vector<int> vs;
    for (int i = 0; i < n; ++i) {
      if (!stk.empty() && stk.back() == t[i]) {
        vs.back() = 0;
        continue;
      }
      while (!stk.empty() && stk.back().x == t[i].x) {
        stk.pop_back();
        vs.pop_back();
      }
      while (stk.size() >= 2 && ((stk.back() - stk[stk.size() - 2]) * (t[i] - stk.back())) >= 0) {
        stk.pop_back();
        vs.pop_back();
      }
      stk.push_back(t[i]);
      vs.push_back(1);
    }
    int i = 0;
    int ans = 0;
    while (i + 1 < stk.size() && stk[i + 1].y >= stk[i].y) ++i;
    for (int j = i; j < stk.size(); ++j) ans += vs[j];
    //for (int j = i; j < stk.size(); ++j) cerr << "TAKE " << stk[j].x << ' ' << stk[j].y << '\n';
    cout << ans << '\n';
  }

#ifdef ELEGIA
  LOG("Time: %dms\n", int ((clock()
          -nol_cl) / (double)CLOCKS_PER_SEC * 1000));
#endif
  return 0;
}