/*************************************************************************
    > File Name: hdu1542.cpp
    > Author: ALex
    > Mail: 405045132@qq.com 
    > Created Time: 2015年01月15日 星期四 11时13分38秒
 ************************************************************************/

#include <map>
#include <set>
#include <queue>
#include <stack>
#include <vector>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

const int N = 210;

int n, cnt;
struct node
{
	double l, r;
	double h;
	int flag;
}lines[N << 1];

struct seg
{
	int l, r;
	int add;
	double len;
}tree[N << 2];

double xis[N];

int cmp (node a, node b)
{
	return a.h < b.h;
}

int BinSearch (double val)
{
	int l = 1;
	int r = cnt;
	int mid;
	while (l <= r)
	{
		mid = (l + r) >> 1;
		if (xis[mid] < val)
		{
			l = mid + 1;
		}
		else if (xis[mid] > val)
		{
			r = mid - 1;
		}
		else
		{
			break;
		}
	}
	return mid;
}

void build (int p, int l, int r)
{
	tree[p].l = l;
	tree[p].r = r;
	tree[p].len = 0;
	tree[p].add = 0;
	if (l == r)
	{
		return;
	}
	int mid = (l + r) >> 1;
	build (p << 1, l, mid);
	build (p << 1 | 1, mid + 1, r);
}

void pushup (int p)
{
	if (tree[p].add)
	{
		tree[p].len = xis[tree[p].r + 1] - xis[tree[p].l]; 
	}
	else if (tree[p].l == tree[p].r)
	{
		tree[p].len = 0;
	}
	else
	{
		tree[p].len = tree[p << 1].len + tree[p << 1 | 1].len;
	}
}

void update (int p, int l, int r, int val)
{
	if (l == tree[p].l && r == tree[p].r)
	{
		tree[p].add += val;
		pushup(p);
		return;
	}
	//这里无需down，因为对应每一条直线，插入之后一定有删除操作
	int mid = (tree[p].l + tree[p].r) >> 1;
	if (r <= mid)
	{
		update (p << 1, l, r, val);
	}
	else if (l > mid)
	{
		update (p << 1 | 1, l, r, val);
	}
	else
	{
		update (p << 1, l, mid, val);
		update (p << 1 | 1, mid + 1, r, val);
	}
	pushup (p);
}

int main()
{
	int icase = 1;
	while (~scanf("%d", &n), n)
	{
		double x1, y1, x2, y2;
		cnt = 0;
		for (int i = 1; i <= n; ++i)
		{
			scanf("%lf%lf%lf%lf", &x1, &y1, &x2, &y2);
			lines[i].flag = -1;
			lines[i].l = x1;
			lines[i].r = x2;
			lines[i].h = y2;
			xis[++cnt] = x1;
			xis[++cnt] = x2;
			lines[i + n].l = x1;
			lines[i + n].r = x2;
			lines[i + n].h = y1;
			lines[i + n].flag = 1;
		}
		sort (lines + 1, lines + 2 * n + 1, cmp);
		sort (xis + 1, xis + cnt + 1);
		cnt = unique (xis + 1, xis + 1 + cnt) - xis - 1;
		double ans = 0;
		build (1, 1, cnt);
		int l = BinSearch (lines[1].l);
		int r = BinSearch (lines[1].r) - 1;
		update (1, l, r, lines[1].flag);
		for (int i = 2; i <= 2 * n; ++i)
		{
			ans += tree[1].len * (lines[i].h - lines[i - 1].h);
			l = BinSearch (lines[i].l);
			r = BinSearch (lines[i].r) - 1;
			update (1, l, r, lines[i].flag);
		}
		printf("Test case #%d\n", icase++);
		printf("Total explored area: %.2f\n\n", ans);
	}
	return 0;
}