#include <iostream>#include <cstring>#include <cstdio>#include <cmath>#include <vector>using namespace std;#define FOR(i,A,s)  for(int i = A[s]; i != s; i = A[i])#define exp 1e-8const int MAX = 111111, MAXR = 1111, MAXC = 1111;int n, m, k, t;struct DLX {    int n, Size;//Size为尾指针，真正大小    int row[MAX], col[MAX];//记录每个点的行列    int U[MAX], D[MAX], R[MAX], L[MAX]; //4个链表    int S[MAXC];//每列1的个数    int ncnt, ans[MAXR];    void init (int n) {        this->n = n;        //增加n+1个辅助链表，从0到n        for (int i = 0; i <= n; i++)            U[i] = D[i] = i, L[i] = i - 1, R[i] = i + 1;        R[n] = 0, L[0] = n; //头尾相接        Size = n + 1;        memset (S, 0, sizeof S);    }    //逐行添加    void addRow (int r, int columns[111]) {        int first = Size;        for (int i = 1; i <= n ; i++) {            if (columns[i] == 0) continue;            int c = i;            L[Size] = Size - 1, R[Size] = Size + 1;            U[Size] = U[c], D[Size] = c;//插入第c列            D[U[c]] = Size, U[c] = Size; //注意顺序!!!            row[Size] = r, col[Size] = c;            Size++, S[c]++;        }        if (Size > first)            R[Size - 1] = first, L[first] = Size - 1; //头尾相接    }    void Remove (int c) {        //精确覆盖//        L[R[c]] = L[c], R[L[c]] = R[c];//        FOR (i, D, c)//                     FOR (j, R, i)//                            U[D[j]] = U[j], D[U[j]] = D[j], --S[col[j]];        //重复覆盖        for (int i = D[c]; i != c; i = D[i])            L[R[i]] = L[i], R[L[i]] = R[i];    }    void Restore (int c) {//        FOR (i, U, c)//                     FOR (j, L, i)//                            ++S[col[j]], U[D[j]] = j, D[U[j]] = j;//        L[R[c]] = c, R[L[c]] = c;        //重复覆盖        for (int i = U[c]; i != c; i = U[i])            L[R[i]] = R[L[i]] = i;    }    bool v[MAX];    int ff()    {        int ret = 0;        for (int c = R[0]; c != 0; c = R[c]) v[c] = true;        for (int c = R[0]; c != 0; c = R[c])            if (v[c])            {                ret++;                v[c] = false;                for (int i = D[c]; i != c; i = D[i])                    for (int j = R[i]; j != i; j = R[j])                        v[col[j]] = false;            }        return ret;    }    bool dfs (int d) {        if (d + ff() > k) return 0;        if (R[0] == 0) {            ncnt = d;            return d <= k;        }        int c = R[0];        for (int i = R[0]; i != 0; i = R[i])            if (S[i] < S[c])                c = i;        //Remove (c);//精确覆盖        FOR (i, D, c) {            Remove (i);//重复覆盖            ans[d] = row[i];            //FOR (j, R, i) Remove (col[j]);            FOR (j, R, i) Remove (j);            if (dfs (d + 1) ) return 1;            //FOR (j, L, i) Restore (col[j]);            FOR (j, L, i) Restore (j);            Restore (i);//重复覆盖        }        //Restore (c);//精确覆盖        return 0;    }    bool solve (vector<int> &v) {        v.clear();        if (!dfs (0) ) return 0;        for (int i = 0; i < ncnt; i++) v.push_back (ans[i]);        return 1;    }} f;struct node {    int x, y;} g[100], Ra[100];int columns[111][111];double dis[111][111];inline double getdis (node a, node b) {    return sqrt (double ( (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y) ) );}bool make (double mid) {    f.init (n);    for (int i = 1; i <= m; i++)        for (int j = 1; j <= n; j++)            columns[i][j] = dis[i][j] <= mid;    for (int i = 1; i <= m; i++)        f.addRow (i, columns[i]);    return f.dfs (0);}int main() {    scanf ("%d", &t);    while (t--) {        scanf ("%d %d %d", &n, &m, &k);        for (int i = 1; i <= n; i++)            scanf ("%d %d", &g[i].x, &g[i].y);        for (int i = 1; i <= m; i++)            scanf ("%d %d", &Ra[i].x, &Ra[i].y);        double l = 1e9, r = 0;        for (int i = 1; i <= m; i++)            for (int j = 1; j <= n; j++) {                dis[i][j]  = getdis (Ra[i], g[j]);                l = min (dis[i][j], l), r = max (r, dis[i][j]);            }        double ans = -1;        while (r - l > 1e-7) {            double mid = (r + l) / 2.;            if (make (mid) ) {                ans = mid;                r = mid - exp;            }            else                l = mid + exp;        }        printf ("%.6f\n", ans);    }    return 0;}