#include <iostream>

#include <algorithm>

#include <cstdio>

#include <math.h>

#include <set>

#include <map>

#include <queue>

#include <string>

#include <string.h>

#include <bitset>

#define REP(i,a,n) for(int i=a;i<=n;++i)

#define PER(i,a,n) for(int i=n;i>=a;--i)

#define hr putchar(10)

#define pb push_back

#define lc (o<<1)

#define rc (lc|1)

#define mid ((l+r)>>1)

#define ls lc,l,mid

#define rs rc,mid+1,r

#define x first

#define y second

#define io std::ios::sync_with_stdio(false)

#define endl '\n'

#define DB(a) ({REP(__i,1,n) cout<<a[__i]<<' ';hr;})

using namespace std;

typedef long long ll;

typedef pair<int,int> pii;

const int P = 1e9+7, INF = 0x3f3f3f3f;

ll gcd(ll a,ll b) {return b?gcd(b,a%b):a;}

ll qpow(ll a,ll n) {ll r=1%P;for (a%=P;n;a=a*a%P,n>>=1)if(n&1)r=r*a%P;return r;}

ll inv(ll x){return x<=1?1:inv(P%x)*(P-P/x)%P;}

//head

const int N = 1e3+10;

int n, cas, cnt, tot;

struct _ {double l,r,h;int v;} e[N];

double b[N], sum[N<<2];

int tag[N<<2];

void pu(int o, int l, int r) {

	if (tag[o]) sum[o] = b[r+1]-b[l];

	else sum[o] = sum[lc]+sum[rc];

}

void update(int o, int l, int r, int ql, int qr, int v) {

	if (ql<=l&&r<=qr) return tag[o]+=v,pu(o,l,r);

	if (mid>=ql) update(ls,ql,qr,v);

	if (mid<qr) update(rs,ql,qr,v);

	pu(o,l,r);

}

void work() {

	cnt=tot=0;

	memset(sum,0,sizeof sum);

	memset(tag,0,sizeof tag);

	REP(i,1,n) {

		double x1, y1, x2, y2;

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

		e[++cnt]={y1,y2,x1,1};

		e[++cnt]={y1,y2,x2,-1};

		b[++tot]=y1,b[++tot]=y2;

	}

	sort(b+1,b+1+tot),tot=unique(b+1,b+1+tot)-b-1;

	sort(e+1,e+1+cnt,[](_ a,_ b){return a.h<b.h;});

	double ans = 0;

	REP(i,1,cnt-1) {

		int l=lower_bound(b+1,b+1+tot,e[i].l)-b;

		int r=lower_bound(b+1,b+1+tot,e[i].r)-b-1;

		update(1,1,tot,l,r,e[i].v);

		ans += sum[1]*(e[i+1].h-e[i].h);

	}

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

}

int main() {

	for (; scanf("%d", &n), n; ) work();

}