#include<bits/stdc++.h>
#define ll long long
#define eps 1e-8
using namespace std;
const int N=100010;
struct point{
    ll x;
    ll y;
}P[N];
ll S[N];
ll S_s[N];
int n;
ll xr,yr,r;
ll M(point a,point b)
{
    return 1ll*a.x*b.y-1ll*b.x*a.y;
}
ll find_area(int left,int right)
{
    if(left<=right)return S_s[right-1]-S_s[left-1]-(M(P[left],P[right]));
    else{
        ll temp=S_s[n-1]-S_s[left-1]+S_s[right-1]+S[n];
        return temp-M(P[left],P[right]);
    }
}
double find_d(int left,int right)
{
    if(left==right)return sqrt(P[left].x*P[left].x+P[left].y*P[left].y)*1.00;
    double d1=sqrt((P[left].x-P[right].x)*(P[left].x-P[right].x)+(P[left].y-P[right].y)*(P[left].y-P[right].y))*1.00;
    double d=M(P[left],P[right])*1.00/d1;
    //printf("%d %d %lf %lf\n",left,right,d1,d);
    return d;
}
int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d",&n);
        scanf("%lld %lld %lld",&xr,&yr,&r);
        for(int i=1;i<=n;i++)
        {
            scanf("%lld %lld",&P[i].x,&P[i].y);
            P[i].x=(P[i].x)-xr*1ll;
            P[i].y=(P[i].y)-yr*1ll;
        }
        S_s[0]=0ll;
        for(int i=1;i<=n;i++)
        {
            if(i<n)S[i]=M(P[i],P[i+1]);
            else S[i]=M(P[i],P[1]);
            //printf("%lld\n",S[i]);
            S_s[i]=S_s[i-1]+S[i];
        }
        int curr=1;
        ll ans=0ll;
        for(int i=1;i<=n;i++)
        {
            while(find_d(i,(curr%n)+1)+eps>=1.00*r)
            {
                curr=(curr%n)+1;
                ans=max(1ll*ans,1ll*find_area(i,curr));
            }
        }
        curr=n;
        for(int i=n;i>=1;i--)
        {
            while(find_d(i,((curr+n-2)%n)+1)-eps<=-1.00*r)
            {
                curr=((curr+n-2)%n)+1;
                ans=max(ans*1ll,1ll*find_area(curr,i));
            }
        }
        printf("%lld\n",ans);
        
    }
    return 0;
}