#include <algorithm>
#include <iomanip>
#include <iostream>
#include <queue>
#include <vector>

using namespace std;

int c, n;
vector<int> u(101);
vector<int> u_size(101, 0);

int find(int idx) {
  if (idx == u[idx]) return idx;
  return u[idx] = find(u[idx]);
}

int unite(int a, int b) {
  int ua = u[a];
  int ub = u[b];
  u_size[ua] += u_size[ub];
  return u[b] = ua;
}

bool is_same_union(int a, int b) { return find(a) == find(b); }

int main(void) {
  cin >> c;
  while (c--) {
    cin >> n;
    vector<pair<double, double>> v;
    priority_queue<pair<double, pair<int, int>>> pq;
    for (int i = 0; i < n; ++i) {
      double x, y;
      cin >> x >> y;
      v.push_back({x, y});
      u[i] = i;
      u_size[i] = 1;
      for (int j = 0; j < i; ++j) {
        double xdiff = v[j].first - v[i].first;
        double ydiff = v[j].second - v[i].second;
        double dist = xdiff * xdiff + ydiff * ydiff;
        pq.push({-dist, {i, j}});
      }
    }

    double ans = 0;

    while (!pq.empty()) {
      double dist = -pq.top().first;
      int a = pq.top().second.first;
      int b = pq.top().second.second;
      pq.pop();
      if (!is_same_union(a, b)) {
        int united = unite(a, b);
        ans = max(ans, dist);
        if (u_size[united] == n) {
          break;
        }
      }
    }

    cout << setprecision(2) << fixed << sqrt(ans) << "\n";
  }
  return 0;
}