import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.*;

/**
 * @author Ryan
 * @data 2020/05/07 - 周四
 */
public class 袭击119 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int T = sc.nextInt();
        for (int i = 0; i < T; i++) {
            int N = sc.nextInt();
            MyPoint[] ps = new MyPoint[2 * N];
            MyPoint p;
            double x, y;
            double dist = Double.MAX_VALUE;
            for (int j = 0; j < N; j++) {
                x = sc.nextDouble();
                y = sc.nextDouble();
                p = new MyPoint(x, y, 1);
                ps[j] = p;
            }
            for (int j = 0; j < N; j++) {
                x = sc.nextInt();
                y = sc.nextInt();
                p = new MyPoint(x, y, 2);
                ps[N + j] = p;
            }
            if (dist < 1) {
                System.out.printf("%.3f %n", dist);
            }
            Arrays.sort(ps, comp);
            dist = findMinDist(ps, 0, 2 * N - 1);
            System.out.printf("%.3f %n", Math.sqrt(dist));
        }
    }

    static Comparator<MyPoint> comp = new Comparator<MyPoint>() {
        @Override
        public int compare(MyPoint a1, MyPoint a2) {
            return a1.x-a2.x > 0 ? 1:-1;
        }};
    private static double findMinDist(MyPoint[] ps, int l, int r) {
        int mid = l + (r - l) / 2;
        double min = Double.MAX_VALUE;
        if (l >= r) {
            return min;
        } else if (l + 1 == r) {
            return  calculateDist(ps[l], ps[r]);
        }
        min = Math.min(findMinDist(ps, l, mid), findMinDist(ps,mid +1, r));
        int cnt = 0;
        MyPoint[] t = new MyPoint[r - l + 1];
        double lowBound = ps[mid].x - Math.sqrt(min);
        double upBound = ps[mid].x + Math.sqrt(min);
        for (int i = l; i <= r; i++) {
            if (ps[i].x >= lowBound && ps[i].x <= upBound) {
                t[cnt++] = ps[i];
            }
        }
        double team = 0;
        for (int i = 0; i < cnt - 1; i++) {
            for (int j = i + 1; j < cnt ; j++) {
                team = calculateDist(ps[i], ps[j]);
                min = Math.min(min, team);

            }
        }
        return min;
    }

    private static double calculateDist(MyPoint p, MyPoint p1) {
        if (p1.f == p.f) {
            return Double.MAX_VALUE;
        }
        return (p.x - p1.x) * (p.x - p1.x) + (p.y - p1.y) * (p.y - p1.y);
    }

    static class MyPoint {
        double x;
        double y;
        int f;
        public MyPoint(double x, double y, int f) {
            this.x = x;
            this.y = y;
            this.f = f;
        }
    }
}