//STATUS:C++_AC_2094MS_4880KB

 #include <functional>

 #include <algorithm>

 #include <iostream>

 //#include <ext/rope>

 #include <fstream>

 #include <sstream>

 #include <iomanip>

 #include <numeric>

 #include <cstring>

 #include <cassert>

 #include <cstdio>

 #include <string>

 #include <vector>

 #include <bitset>

 #include <queue>

 #include <stack>

 #include <cmath>

 #include <ctime>

 #include <list>

 #include <set>

 #include <map>

 using namespace std;

 //#pragma comment(linker,"/STACK:102400000,102400000")

 //using namespace __gnu_cxx;

 //define

 #define pii pair<int,int>

 #define mem(a,b) memset(a,b,sizeof(a))

 #define lson l,mid,rt<<1

 #define rson mid+1,r,rt<<1|1

 #define PI acos(-1.0)

 //typedef

 typedef __int64 LL;

 typedef unsigned __int64 ULL;

 //const

 const int N=;

 const int INF=0x3f3f3f3f;

 const int MOD=,STA=;

 const LL LNF=1LL<<;

 const double EPS=1e-;

 const double OO=1e30;

 const int dx[]={-,,,};

 const int dy[]={,,,-};

 const int day[]={,,,,,,,,,,,,};

 //Daily Use ...

 inline int sign(double x){return (x>EPS)-(x<-EPS);}

 template<class T> T gcd(T a,T b){return b?gcd(b,a%b):a;}

 template<class T> T lcm(T a,T b){return a/gcd(a,b)*b;}

 template<class T> inline T lcm(T a,T b,T d){return a/d*b;}

 template<class T> inline T Min(T a,T b){return a<b?a:b;}

 template<class T> inline T Max(T a,T b){return a>b?a:b;}

 template<class T> inline T Min(T a,T b,T c){return min(min(a, b),c);}

 template<class T> inline T Max(T a,T b,T c){return max(max(a, b),c);}

 template<class T> inline T Min(T a,T b,T c,T d){return min(min(a, b),min(c,d));}

 template<class T> inline T Max(T a,T b,T c,T d){return max(max(a, b),max(c,d));}

 //End

 struct Node{

     double x,y;

     int id,index;

     Node(){}

     Node(double _x,double _y,int _index):x(_x),y(_y),index(_index){}

 }nod[N],temp[N];

 int n;

 double dist(Node &a,Node &b)

 {

     return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));

 }

 bool cmpxy(Node a,Node b)

 {

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

 }

 bool cmpy(Node a,Node b)

 {

     return a.y<b.y;

 }

 pii Closest_Pair(int l,int r)

 {

     if(l==r || l+==r)return pii(l,r);

     double d,d1,d2;

     int i,j,k,mid=(l+r)/;

     pii pn1=Closest_Pair(l,mid);

     pii pn2=Closest_Pair(mid+,r);

     if(pn1.first==pn1.second || nod[pn1.first].index==nod[pn1.second].index)

         d1=OO;

     else d1=dist(nod[pn1.first],nod[pn1.second]);

     if(pn2.first==pn2.second || nod[pn2.first].index==nod[pn2.second].index)

         d2=OO;

     else d2=dist(nod[pn2.first],nod[pn2.second]);

     pii ret;

     d=Min(d1,d2);

     ret=d1<d2?pn1:pn2;

     for(i=l,k=;i<=r;i++){

         if(fabs(nod[mid].x-nod[i].x)<=d){

             temp[k++]=nod[i];

         }

     }

     sort(temp,temp+k,cmpy);

     for(i=;i<k;i++){

         for(j=i+;j<k && fabs(temp[j].y-temp[i].y)<d;j++){

             if(dist(temp[i],temp[j])<d && (temp[i].index^temp[j].index)){

                 d=dist(temp[i],temp[j]);

                 ret=make_pair(temp[i].id,temp[j].id);

             }

         }

     }

     return ret;

 }

 void Init()

 {

     int i,t;

     double x,y;

     scanf("%d",&t);

     n=t<<;

     for(i=;i<t;i++){

         scanf("%lf%lf",&x,&y);

         nod[i]=Node(x,y,);

     }

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

         scanf("%lf%lf",&x,&y);

         nod[i]=Node(x,y,);

     }

     sort(nod,nod+n,cmpxy);

     for(i=;i<n;i++)nod[i].id=i;

 }

 int main(){

  //   freopen("in.txt","r",stdin);

     int T,i,j;

     scanf("%d",&T);

     while(T--)

     {

         Init();

         pii ans=Closest_Pair(,n-);

         printf("%.3lf\n",dist(nod[ans.first],nod[ans.second]));

     }

     return ;

 }