int main()
{
int m,nn,l,i,T,a,b;
double w;
scanf("%d",&T);
s = 0;
while(T--){
scanf("%d%d%d",&m,&nn,&l);
t = m+nn+1;
memset(con,0,sizeof(con));
for(i = 1; i <= m; i++){
scanf("%lf",&w);
con[s][i] = log(w);
}
for(i = m+1; i <= m+nn; i++){
scanf("%lf",&w);
con[i][t] = log(w);
}
for(i = 0; i < l; i++){
scanf("%d%d",&a,&b);
con[a][b+m] = 1e10;
}
n = m+nn+2;
printf("%.4lf\n",exp(Maxflow()));
}
return 0;
}
void AlphaBetaSwap(){
INT32T alpha, beta;
for (alpha = 0; alpha < numLabels; alpha++)
for (beta = alpha + 1; beta < numLabels; beta++){
ModifyMap(alpha, beta);
Maxflow();
ChangeLabel(alpha, beta);
}
}
void TestMaxflow(){
InitMap();
N = 6;
source = 0;
sink = N - 1;
AddEdge(source, 1, 100, 0);
AddEdge(1, 2, 110, 0);
AddEdge(2, sink, 20, 0);
AddEdge(source, 3, 30, 0);
AddEdge(3, 4, 200, 0);
AddEdge(4, sink, 201, 0);
AddEdge(2, 4, 11, 0);
AddEdge(4, 2, 30, 0);
Maxflow();
}
