//Author: Kevin
#include<bits/stdc++.h>
//#pragma GCC optimize("O2")
using namespace std;
#define ll long long
#define ull unsigned ll
#define pb emplace_back
#define mp make_pair
#define ALL(x) (x).begin(),(x).end()
#define rALL(x) (x).rbegin(),(x).rend()
#define srt(x) sort(ALL(x))
#define rev(x) reverse(ALL(x))
#define rsrt(x) sort(rALL(x))
#define sz(x) (int)(x.size())
#define inf 0x3f3f3f3f
#define pii pair<int,int>
#define lb(v,x) (int)(lower_bound(ALL(v),x)-v.begin())
#define ub(v,x) (int)(upper_bound(ALL(v),x)-v.begin())
#define uni(v) v.resize(unique(ALL(v))-v.begin())
#define longer __int128_t
#define double long double
#define x first
#define y second
void die(string S){puts(S.c_str());exit(0);}
using point=pair<ll,ll>;
point p[5005],sp,qp[5005];
int n,q;
vector<array<int,3>> tri;
const ll operator ^(const point &a,const point &b)
{
	return a.x*b.y-a.y*b.x;
}
const point operator -(const point &a,const point &b)
{
	return point(a.x-b.x,a.y-b.y);
}
bool sameSide(point M,point N,point A,point B)
{
	return ((M-N)^(A-N))*((M-N)^(B-N))>=0;
}
bool inside(point A,point B,point C,point P)
{
	return sameSide(A,B,C,P)&&sameSide(A,C,B,P)&&sameSide(B,C,A,P);
}
ll dist2(const point &a,const point &b)
{
	return (a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y);
}
double dist(const point &a,const point &b)
{
	return sqrt(dist2(a,b));
}
void decomp(vector<int> vec)
{
	if(sz(vec)==3)
	{
		tri.push_back({vec[0],vec[1],vec[2]});
		return ;
	}
	if(((p[vec[2]]-p[vec[1]])^(p[vec[0]]-p[vec[1]]))<0)
	{
		vec.pb(vec[0]);
		vec.erase(vec.begin());
		decomp(vec);
		return ;
	}
	pair<ll,int> pr=mp(1e18,-1);
	for(int i=3;i<sz(vec);i++)
		if(inside(p[vec[0]],p[vec[1]],p[vec[2]],p[vec[i]]))
			pr=min(pr,mp(dist2(p[vec[1]],p[vec[i]]),i));
	if(pr.second==-1)
	{
		tri.push_back({vec[0],vec[1],vec[2]});
		vec.erase(vec.begin()+1);
		decomp(vec);
	}
	else
	{
		vector<int> v1,v2;
		for(int i=1;i<=pr.second;i++)
			v1.pb(vec[i]);
		for(int i=pr.second;i<sz(vec);i++)
			v2.pb(vec[i]);
		v2.pb(vec[0]);
		v2.pb(vec[1]);
		decomp(v1);
		decomp(v2);
	}
}
vector<int> G[5005];
int getIndex(const point &po)
{
	for(int i=1;i<=sz(tri);i++)
		if(inside(p[tri[i-1][0]],p[tri[i-1][1]],p[tri[i-1][2]],po))
			return i;
	assert(0);
	return -1;
}
vector<int> ret;
bool dfs(int u,int fa,int nd)
{
	ret.pb(u);
	if(u==nd)
		return true;
	for(auto v:G[u])
		if(v!=fa)
			if(dfs(v,u,nd))
				return true;
	ret.pop_back();
	return false;
}
vector<int> getRoute(int st,int nd)
{
	ret.clear();
	assert(dfs(st,0,nd));
	return ret;
}
pii getDiagonal(int A,int B)
{
	vector<int> ans;
	map<int,int> Mp;
	for(int i=0;i<3;i++)
		Mp[tri[A-1][i]]++;
	for(int i=0;i<3;i++)
		Mp[tri[B-1][i]]++;
	for(auto pr:Mp)
		if(pr.second==2)
			ans.pb(pr.first);
	assert(sz(ans)==2);
	for(int i=0;i<3;i++)
		if(ans[1]==tri[A-1][i]&&ans[0]==tri[A-1][(i+1)%3])
		{
			swap(ans[0],ans[1]);
			break;
		}
	return mp(ans[0],ans[1]);
}
double getAnswer(int st,int nd,point A,point B,vector<int> route,bool flag)
{
	if(sz(route)==1) return dist(A,B);
	p[0]=A;
	p[n+1]=B;
	deque<int> dq;
	int apex=0;
	double ans=0;
	vector<pii> vd;
	for(int i=1;i<sz(route);i++)
		vd.pb(getDiagonal(route[i-1],route[i]));
	dq.push_back(0);
	if(p[vd[0].first]!=p[0])
		dq.push_front(vd[0].first);
	if(p[vd[0].second]!=p[0])
		dq.push_back(vd[0].second);
	auto extend=[&](int a,int b)
	{
		if(p[b]==p[dq.front()]||p[b]==p[dq.back()])
			swap(a,b);
		if(p[a]==p[dq.front()])
		{
			if(p[b]==p[dq.back()])
				return ;
			while(p[dq.back()]!=p[apex]&&p[b]!=p[dq.back()]&&((p[b]-p[dq[sz(dq)-2]])^(p[dq.back()]-p[dq[sz(dq)-2]]))>0)
				dq.pop_back();
			if(p[dq.back()]!=p[apex])
			{
				if(p[b]!=p[dq.back()])
					dq.push_back(b);
			}
			else
			{
				while(sz(dq)>1&&((p[b]-p[dq.back()])^(p[dq[sz(dq)-2]]-p[dq.back()]))>0)
				{
					ans+=dist(p[dq.back()],p[dq[sz(dq)-2]]);
					dq.pop_back();
					apex=dq.back();
				}
				if(p[b]!=p[dq.back()])
					dq.push_back(b);
			}
		}
		else
		{
			if(p[b]==p[dq.front()])
				return ;
			while(p[dq.front()]!=p[apex]&&p[b]!=p[dq[0]]&&((p[b]-p[dq[1]])^(p[dq[0]]-p[dq[1]]))<0)
				dq.pop_front();
			if(p[dq.front()]!=p[apex])
			{
				if(p[b]!=p[dq.front()])
					dq.push_front(b);
			}
			else
			{
				while(sz(dq)>1&&((p[b]-p[dq[0]])^(p[dq[1]]-p[dq[0]]))<0)
				{
					ans+=dist(p[dq[0]],p[dq[1]]);
					dq.pop_front();
					apex=dq[0];
				}
				if(p[b]!=p[dq.front()])
					dq.push_front(b);
			}
		}
	};
	for(int i=1;i<sz(vd);i++)
		extend(vd[i].first,vd[i].second);
	if(flag)
		extend(vd.back().first,n+1);
	else
		extend(vd.back().second,n+1);
	if(p[dq.back()]==p[n+1])
	{
		while(p[dq.back()]!=p[apex])
		{
			ans+=dist(p[dq.back()],p[dq[sz(dq)-2]]);
			dq.pop_back();
		}
		return ans;
	}
	else
	{
		while(p[dq.front()]!=p[apex])
		{
			ans+=dist(p[dq[0]],p[dq[1]]);
			dq.pop_front();
		}
		return ans;
	}
}
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int t;
	cin>>t;
	while(t--)
	{
		cin>>n;
		for(int i=1;i<=n;i++)
			G[i].clear();
		for(int i=1;i<=n;i++)
			cin>>p[i].x>>p[i].y;
		cin>>sp.x>>sp.y;
		cin>>q;
		for(int i=1;i<=q;i++)
			cin>>qp[i].x>>qp[i].y;
		vector<int> vec;
		for(int i=1;i<=n;i++)
			vec.pb(i);
		tri.clear();
		decomp(vec);
		map<pii,int> Mp;
		auto Try=[&](int a,int b,const int &c)
		{
			if(a>b) swap(a,b);
			if(Mp.count(mp(a,b)))
			{
				int x=Mp[mp(a,b)];
				G[x].pb(c);
				G[c].pb(x);
			}
			else
				Mp[mp(a,b)]=c;
		};
		for(int i=1;i<=sz(tri);i++)
		{
			Try(tri[i-1][0],tri[i-1][1],i);
			Try(tri[i-1][2],tri[i-1][1],i);
			Try(tri[i-1][0],tri[i-1][2],i);
		}
		int st=getIndex(sp);
		for(int i=1;i<=q;i++)
		{
			int nd;
			vector<int> route=getRoute(st,nd=getIndex(qp[i]));
			// rev(route);
			// double ans=getAnswer(nd,st,qp[i],sp,route);
			double ans=min(getAnswer(st,nd,sp,qp[i],route,0),getAnswer(st,nd,sp,qp[i],route,0));
			cout<<fixed<<setprecision(12)<<ans<<endl;
		}
	}
	return 0;
}