#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>#include <climits>#include <string>#include <iostream>#include <map>#include <cstdlib>#include <list>#include <set>#include <queue>#include <stack>using namespace std;typedef long long LL;const int maxn = 105;const double INF = 1e60;const double eps = 1e-9;int level[maxn],n,m,c,q[maxn],qs,qe;double cap[maxn][maxn];int s,t;bool bfs() {    qs = qe = 0;    memset(level,0,sizeof(level));    level[s] = 1;    q[qe++] = s;    while(qs < qe) {        int now = q[qs++];        if(now == t) break;        for(int i = s;i <= t;i++) if(cap[now][i] >= eps) {            if(level[i] == 0) {                q[qe++] = i; level[i] = level[now] + 1;            }        }    }     return level[t];}double dfs(int now,double alpha) {    if(now == t) return alpha;    double sum = 0;    for(int i = s;i <= t && alpha >= eps;i++) {        if(cap[now][i] >= eps && level[i] == level[now] + 1) {            double ret = dfs(i,min(alpha,cap[now][i]));            sum += ret; alpha -= ret;            cap[now][i] -= ret; cap[i][now] += ret;        }    }    if(sum < eps) level[now] = -1;    return sum;}void solve() {    double ans = 0;    while(bfs()) ans += dfs(s,INF);    printf("%.4f\n",exp(ans));}int main() {    int T; scanf("%d",&T);    while(T--) {        memset(cap,0,sizeof(cap));        scanf("%d%d%d",&n,&m,&c);        s = 0; t = n + m + 1;        for(int i = 1;i <= n;i++) {            double tmp; scanf("%lf",&tmp);            cap[s][i] = log(tmp);        }        for(int i = 1;i <= m;i++) {            double tmp; scanf("%lf",&tmp);            cap[i + n][t] = log(tmp);        }        for(int i = 1;i <= c;i++) {            int a,b; scanf("%d%d",&a,&b);            cap[a][b + n] = INF;        }        solve();    }    return 0;}