#include <stdio.h>
#include <iostream>
#include <math.h>
#include <vector>
using namespace std;

typedef struct _PointF
{
    float x, y;
} PointF;

int main(void)
{
    vector<float> output;
    int c = 0;
    cin >> c;
    for(int i=0; i<c; i++)
    {
        vector<PointF> posList;
        int baseNum = 0;
        cin >> baseNum;
        for(int j=0; j<baseNum; j++)
        {
            PointF basePoint = { 0, 0 };
            cin >> basePoint.x >> basePoint.y;
            posList.push_back(basePoint);
        }
        float distance = 0;
        for(int j=0; j<baseNum-1; j++)
        {
            float nearestBase = 10000;
            for(int k=j+1; k<baseNum; k++)
            {
                float temp = 
sqrtf((posList[j].x-posList[k].x)*(posList[j].x-posList[k].x)+(posList[j].y-posList[k].y)*(posList[j].y-posList[k].y));
                if(temp < nearestBase)
                {
                    nearestBase = temp;
                }
            }
            if(distance < nearestBase)
            {
                distance = nearestBase;
            }
        }
        output.push_back(distance);
    }

    for(int i=0; i<c; i++)
        printf("%.2f\n", output[i]);

    return 0;
}