Raid

#include<bits/stdc++.h>
#include<vector>
using namespace std;
const int maxn=1e5+5;
#define REP(i, a, b) for(int i = (a); i <= (b); ++ i)
#define REP(j, a, b) for(int j = (a); j <= (b); ++ j)
#define PER(i, a, b) for(int i = (a); i >= (b); -- i)
#define inf 1e50
template <class T>
inline void rd(T &ret){
    char c;
    ret = 0;
    while ((c = getchar()) < ‘0‘ || c > ‘9‘);
    while (c >= ‘0‘ && c <= ‘9‘){
        ret = ret * 10 + (c - ‘0‘), c = getchar();
    }
}
struct node{
    double x,y;
    int pos;
}p[2*maxn],tmp[2*maxn];
bool cx(node a,node b){return a.x<b.x;}
bool cy(node a,node b){return a.y<b.y;}
double gt(int l,int r){
    if(l==r)return inf;
    int mid=(l+r)/2;
    double ans=min(gt(l,mid),gt(mid+1,r));
    int cnt=0;
    for(int i=l;i<=r;i++){
        if(fabs(p[i].x-p[mid].x)<=ans){
            tmp[++cnt]=p[i];
        }
    }
    sort(tmp+1,tmp+1+cnt,cy);
    for(int i=1;i<=cnt;i++){
        for(int j=i+1;j<=cnt&&tmp[j].y-tmp[i].y<=ans;j++){
            double t;
            ans=min(ans,t=(tmp[j].pos==tmp[i].pos?inf:sqrt((tmp[i].x-tmp[j].x)*(tmp[i].x-tmp[j].x)+(tmp[i].y-tmp[j].y)*(tmp[i].y-tmp[j].y))));
        }
    }
    return ans;
}
int main(){
    int T;
    rd(T);
    while(T--){
        int n;
        rd(n);
        memset(tmp,0,sizeof(tmp));
        memset(p,0,sizeof(p));
        for(int i=1;i<=2*n;i++){
            scanf("%lf %lf",&p[i].x,&p[i].y);
            p[i].pos=i<=n?1:0;
        }
        sort(p+1,p+2*n+1,cx);
        printf("%.3f\n",gt(1,2*n));
    }
}