#include <iostream>
#include <vector>
#include <cstring>
#include <math.h>
#include <algorithm>
using namespace std;
pair<double,double> camps[101];
bool visit[101];
int n;
double x,y;
double getDistance(int i, int j){
    return sqrt(pow(camps[i].first-camps[j].first,2)+pow(camps[i].second-camps[j].second,2));
}
void possible(int index, double dist){
    for(int i=0;i<n;++i)
        if(i!=index && !visit[i] && getDistance(index,i)<=dist) {
            visit[i]=true;
            possible(i,dist);
        }
}
bool upper(int index, double dist){
    memset(visit, 0, sizeof(visit));
    visit[0] = true;
    possible(0,dist);
    bool can = true;
    for(int i=0;i<n;++i)
        if(!visit[i]) can = false;
    return can;
}
int main(){
    int c;
    scanf("%d", &c);
    while(c--){
        scanf("%d", &n);
        for(int i=0;i<n;++i){
            scanf("%lf %lf", &x,&y);
            camps[i] = pair<double,double>(x,y);
        }
        vector<double> dists;
        for(int i=0;i<n;++i)
            for(int j=0;j<n;++j)
                dists.push_back(getDistance(i,j));
        sort(dists.begin(), dists.end());
        int lo=0,hi=dists.size()-1;
        while(lo<hi){
            int mid=(lo+hi)/2;
            if(mid==lo) {
                if(!upper(0,dists[mid])) lo = hi;
                break;
            } else {
                if(upper(0,dists[mid])) hi=mid;
                else lo=mid;
            }
        }
        printf("%.02lf\n",dists[lo]);
    }
    return 0;
}