#include<bits/stdc++.h>

#define il inline

#define Rg register

#define go(i,a,b) for(Rg int i=a;i<=b;++i)

#define yes(i,a,b) for(Rg int i=a;i>=b;--i)

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

#define ll long long

#define db double

#define inf 2100000000

using namespace std;

il int read()

{

    Rg int x=,y=;char c=getchar();

    while(c<''||c>''){if(c=='-')y=-;c=getchar();}

    while(c>=''&&c<=''){x=(x<<)+(x<<)+c-'';c=getchar();}

    return x*y;

}

int T,n;

struct node{int x,y;bool tp;}a[(int)1e5*+],tmp[(int)1e5*+];

il bool cmp(node x,node y){if(x.x==y.x)return x.y<y.y;return x.x<y.x;}

il bool cmp1(node x,node y){return x.y<y.y;}

il ll dis(node x,node y){db xx=x.x-y.x,yy=x.y-y.y;return xx*xx+yy*yy;}

il ll sol(int l,int r)

{

    if(l>r || l==r)return inf;

    if(l+==r)

    {

        if(a[l].tp!=a[r].tp){return dis(a[l],a[r]);}

        else return inf;

    }

    Rg int mid=(l+r)>>,ct=;

    ll mins=min(sol(l,mid),sol(mid+,r));

    go(i,l,r){if((a[i].x-a[mid].x)*(a[i].x-a[mid].x)<=mins)tmp[++ct]=a[i];}

    sort(tmp+,tmp+ct+,cmp1);

    go(i,,ct)

        go(j,i+,ct)

    {

        if((tmp[j].y-tmp[i].y)*(tmp[j].y-tmp[i].y)>mins)break;

        if(tmp[i].tp!=tmp[j].tp)mins=min(mins,dis(tmp[i],tmp[j]));

    }

    return mins;

}

int main()

{

    T=read();

    while(T--)

    {

        n=read();

        go(i,,n)a[i]=(node){read(),read(),};

        go(i,,n)a[i+n]=(node){read(),read(),};

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

        printf("%.3lf\n",sqrt(sol(,*n)));

    }

    return ;

}