#include <algorithm>

#include <bitset>

#include <cctype>

#include <cerrno>

#include <clocale>

#include <cmath>

#include <complex>

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <ctime>

#include <deque>

#include <exception>

#include <fstream>

#include <functional>

#include <limits>

#include <list>

#include <map>

#include <iomanip>

#include <ios>

#include <iosfwd>

#include <iostream>

#include <istream>

#include <ostream>

#include <queue>

#include <set>

#include <sstream>

#include <stdexcept>

#include <streambuf>

#include <string>

#include <utility>

#include <vector>

#include <cwchar>

#include <cwctype>

#include <stack>

#include <limits.h>

using namespace std;

#define MAXN 100010

const double INF = 1e10;

int T,i,n;

struct info

{

        double x,y;

        int opt;

} a[MAXN<<];

inline bool cmpx(info a,info b)

{

        return a.x != b.x ? a.x < b.x : a.y < b.y;

}

inline bool cmpy(info a,info b)

{

        return a.y < b.y;

}

double dist(info a,info b)

{

        return (a.opt != b.opt) ? sqrt(abs(a.x - b.x) * abs(a.x - b.x) + abs(a.y - b.y) * abs(a.y - b.y)) : INF;

}

inline double Closest_Pair(int l,int r)

{

        int i,j,mid,len = ;

        static info s[MAXN];

        double d;

        if (l == r) return INF;

        if (l +  == r) return dist(a[l],a[r]);

        mid = (l + r) >> ;

        d = min(Closest_Pair(l,mid),Closest_Pair(mid+,r));

        for (i = l; i <= r; i++)

        {

                if (abs(a[mid].x - a[i].x) <= d) s[++len] = a[i];

        }

        sort(s+,s+len+,cmpy);

        for (i = ; i <= len; i++)

        {

                for (j = i + ; j <= len && s[j].y - s[i].y <= d; j++)

                {

                        d = min(d,dist(s[i],s[j]));

                }

        }

        return d;

}

int main()

{

        scanf("%d",&T);

        while (T--)

        {

                scanf("%d",&n);

                for (i = ; i <= n; i++)

                {

                        scanf("%lf%lf",&a[i].x,&a[i].y);

                        a[i].opt = ;

                }

                for (i = n + ; i <=  * n; i++)

                {

                        scanf("%lf%lf",&a[i].x,&a[i].y);

                        a[i].opt = ;

                }

                sort(a+,a+*n+,cmpx);

                printf("%.3lf\n",Closest_Pair(,n<<));

        }

        return ;

}