#include<bits/stdc++.h>

using namespace std;
#define ll long long

const int N = 205, M = 405;
int T, n, cnt, xl[N], xr[N], yl[N], yr[N], x[M], y[M];
double dis[M][M];
bool vis[M][M];
priority_queue<pair<double,int>, vector<pair<double,int> >, greater<pair<double,int> > > q;
void work(int a, int b, int c, int d){
    int k=0;
    for(int i=1; i<=n; ++i)
        k+=(xl[i]<=x[a] && x[a]<=xr[i] && yl[i]<=y[b] && y[b]<=yr[i] && xl[i]<=x[c] && x[c]<=xr[i] && yl[i]<=y[d] && y[d]<=yr[i]);
    double ti=abs(x[a]-x[c]+y[b]-y[d])/(k+1.);
    if(dis[a][b]+ti<dis[c][d])
        q.push(make_pair(dis[c][d]=dis[a][b]+ti, c*(cnt+1)+d));
}
int main() {
    scanf("%d", &T);
    while(T--){
        scanf("%d", &n), cnt=0;
        for(int i=1; i<=n; ++i){
            scanf("%d%d%d%d", xl+i, yl+i, xr+i, yr+i);
            x[++cnt]=xl[i], y[cnt]=yl[i], x[++cnt]=xr[i], y[cnt]=yr[i];
        }
        scanf("%d%d%d%d", xl, yl, xr, yr);
        x[++cnt]=xl[0], y[cnt]=yl[0], x[++cnt]=xr[0], y[cnt]=yr[0];
        sort(x+1, x+cnt+1), sort(y+1, y+cnt+1);
        for(int i=1; i<=cnt; ++i) for(int j=1; j<=cnt; ++j)
            dis[i][j]=1e10, vis[i][j]=0;
        for(int i=1; i<=cnt; ++i) for(int j=1; j<=cnt; ++j)
            if(x[i]==xl[0] && y[j]==yl[0])
                q.push(make_pair(dis[i][j]=0, i*(cnt+1)+j));
        while(!q.empty()){
            pair<double,int> u=q.top();
            q.pop();
            int xx=u.second/(cnt+1), yy=u.second%(cnt+1);
            if(vis[xx][yy]) continue;
            vis[xx][yy]=1;
            if(x[xx]==xr[0] && y[yy]==yr[0]){
                printf("%.5lf\n", dis[xx][yy]);
                while(!q.empty()) q.pop();
                break;
            }
            if(xx>1) work(xx, yy, xx-1, yy);
            if(xx<cnt) work(xx, yy, xx+1, yy);
            if(yy>1) work(xx, yy, xx, yy-1);
            if(yy<cnt) work(xx, yy, xx, yy+1);
        }
    }
    return 0;
}