/*

Problem: 1151        User: 96655

Memory: 716K        Time: 0MS

Language: G++        Result: Accepted

*/

#include <iostream>

#include <algorithm>

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <string>

#include <stack>

#include <queue>

#include <cmath>

#include <vector>

using namespace std;

const int maxn=;

double y[maxn*];

struct Line

{

    int co;

    double x,y1,y2;

    void fun(double a,double b,double c,int d)

    {

        x=a;

        y1=b;

        y2=c;

        co=d;

    }

    bool operator<(const Line &e)const

    {

        return x<e.x;

    }

}line[maxn*];

struct Node

{

    double s,t,len;

    int co;

    void change(int o)

    {

        co+=o;

        if(co==) len=;

        else len=t-s;

    }

};

struct Segtree

{

    Node tree[maxn*];

    void build(int l,int r,int o)

    {

       tree[o].s=y[l];tree[o].t=y[r];

       tree[o].co=;tree[o].len=;

       if(l+<r)

       {

          int m=(l+r)>>;

          build(l,m,o*);

          build(m,r,o*+);

       }

    }

    void pushup(int o)

    {

      tree[o].len=tree[o*].len+tree[o*+].len;

    }

    void update(int l,int r,int o,Line e)

    {

        if(l+==r)

        {

           tree[o].change(e.co);

           return;

        }

        int m=(l+r)>>;

        if(e.y1<tree[o*].t)update(l,m,o*,e);

        if(e.y2>tree[o*+].s)update(m,r,o*+,e);

        pushup(o);

    }

}seg;

int main()

{

    int n,ncase=;

    while(~scanf("%d",&n),n)

    {

        int cnt=;

        for(int i=;i<n;i++)

        {

            double x1,x2,y1,y2;

            scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);

            line[cnt].fun(x1,y1,y2,);

            y[cnt++]=y1;

            line[cnt].fun(x2,y1,y2,-);

            y[cnt++]=y2;

        }

        sort(line,line+cnt);

        sort(y,y+cnt);

        int d=;

        for(int i=;i<cnt;i++)

           if(y[i]!=y[i-])y[d++]=y[i];

        double ans=;

        seg.build(,d-,);

        seg.update(,d-,,line[]);

        for(int i=;i<cnt;i++)

        {

           ans+=(line[i].x-line[i-].x)*seg.tree[].len;

           seg.update(,d-,,line[i]);

        }

        printf("Test case #%d\nTotal explored area: %.2f\n\n",++ncase,ans);

    }

    return ;

}