#include <cstdio>
#include <algorithm>

using namespace std ;

double y[300] ;

struct Line{
	double x , y_up , y_down ;
	int mark ;
}line[300] ;		//开始开到110,WA另外三次！！后来看discuss改后就A了! 

struct Node{
	double x ,y_up,y_down ;
	int cover ;
	bool isLeaf ;
}st[400100];

bool cmp(const Line &a , const Line &b)
{
	return a.x<b.x ;
}

void build(int l ,int r , int pos)
{
	st[pos].cover = 0 ;
	st[pos].y_down = y[l] ;
	st[pos].y_up = y[r] ;
	st[pos].x = -1 ;
	st[pos].isLeaf = false ;
	if(l+1 == r)
	{
		st[pos].isLeaf = true ;
		return ;
	}
	int mid = (l+r)>>1 ;
	build(l,mid,pos<<1);
	build(mid,r,pos<<1|1) ;
}

double insert(double x , double y_up , double y_down , int mark , int pos)
{
	if(st[pos].y_down>=y_up || st[pos].y_up<=y_down)
	{
		return 0 ;
	}
	if(st[pos].isLeaf)
	{
		if(st[pos].cover>0)
		{
			double temp = st[pos].x ;
			double area = (x-temp)*(st[pos].y_up-st[pos].y_down) ;
			st[pos].x = x ;
			st[pos].cover += mark ;
			return area ;
		}
		else
		{
			st[pos].x = x ;
			st[pos].cover += mark ;
			return 0 ;
		}
	}
	return insert(x,y_up,y_down,mark,pos<<1)+insert(x,y_up,y_down,mark,pos<<1|1) ;
}

int main()
{
	int n , c = 1;
	while(~scanf("%d",&n) && n)
	{
		int index = 0 ;
		for(int i = 0 ; i < n ; ++i)
		{
			double x1,y1,x2,y2 ;
			scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2) ;
			line[index].x = x1 ;
			line[index].y_down = y1 ;
			line[index].y_up = y2 ;
			y[index] = y1 ;
			line[index++].mark = 1 ;
			
			line[index].x = x2 ;
			line[index].y_down = y1 ;
			line[index].y_up = y2 ;
			y[index] = y2 ;
			line[index++].mark = -1 ;
		}
		sort(y,y+index) ;
		sort(line,line+index,cmp) ;
		build(0,index-1,1) ;
		double area = 0.0 ;
		for(int i = 0 ; i < index ; ++i)
		{
			area += insert(line[i].x,line[i].y_up,line[i].y_down,line[i].mark,1) ;
		}
		printf("Test case #%d\n",c++) ;
		printf("Total explored area: %.2lf\n\n",area) ;
	}
	return 0 ;
}