///POJ1151 Atlantis
///线段树 segment tree 求面积
#include <cstdio>
#include <algorithm>
using namespace std;
const int MAX_ELem = 400;
const int MAX_Line = 200;
struct Node{
short left, right;
bool coverd;
double len;
//short segment;
short count;
bool leftcover, rightcover;
struct Node *lcd, *rcd;
void Build(int, int);
void Update();
void Insert(double, double);
void Delete(double, double);
}SegTree[MAX_ELem];
struct Node *root = &SegTree[0];
struct Data{
double x, y1, y2;
bool left;
}line[MAX_Line];
double node_val[MAX_Line];
int up = 0;
void Node::Build(int l, int r)
{
left = l;
right = r;
coverd = 0;
len = 0;
//segment = 0;
count = 0;
leftcover = rightcover = 0;
if(r-l>1){
int lenid = (l + r) / 2;
lcd = &SegTree[++up];
lcd->Build(l, lenid);
rcd = &SegTree[++up];
rcd->Build(lenid, r);
}
}
void Node::Update()
{
if(count>0){
len = node_val[right] - node_val[left];
//segment = 1;
leftcover = rightcover = 1;
}else if(right-left==1){
len = 0;
//segment= 0;
leftcover = rightcover = 0;
}else{
len = lcd->len + rcd->len;
//segment = lcd->segment + rcd->segment;
//if(lcd->rightcover && rcd->leftcover)segment--;
leftcover = lcd->leftcover;
rightcover = rcd->rightcover;
}
}
void Node::Insert(double l, double r)
{
if(l<=node_val[left] && node_val[right]<=r){
count++;
}else{
if(l<node_val[lcd->right]){
lcd->Insert(l, r);
}
if(r>node_val[rcd->left]){
rcd->Insert(l, r);
}
}
Update();
}
void Node::Delete(double l, double r)
{
if(l<=node_val[left] && node_val[right]<=r){
count--;
}else{
if(l<node_val[lcd->right]){
lcd->Delete(l, r);
}
if(r>node_val[rcd->left]){
rcd->Delete(l, r);
}
}
Update();
}
bool operator < (const Data &a, const Data &b)
{
return a.x < b.x;
}
int main(int argc, char **argv) {
//freopen("in","r",stdin);
//freopen("out","w",stdout);
int i, j, N, tstcs=1;
double x1, y1, ans, x2, y2;
while(scanf("%d",&N),N){
i = 0;
for(j=0;j<N;j++){
scanf("%lf %lf %lf %lf",&x1, &y1, &x2, &y2);
line[i].x = x1; line[i].y1 = y1; line[i].y2 = y2; line[i].left = 1; node_val[i++] = y1;
line[i].x = x2; line[i].y1 = y1; line[i].y2 = y2; line[i].left = 0; node_val[i++] = y2;
}
N *= 2;
sort(line, line+N);
sort(node_val, node_val+N);
j = 1;
for(i=1;i<N;i++){
if(node_val[i]!=node_val[i-1]){
node_val[j++] = node_val[i];
}
}
up = 0;
ans = 0;
//prev = 0;
root->Build(0, j-1);
for(i=0; i<N-1; i++){
if(line[i].left){
root->Insert(line[i].y1, line[i].y2);
}else{
root->Delete(line[i].y1, line[i].y2);
}
ans += (line[i+1].x - line[i].x)*root->len;
//printf("ans = %lf\n",ans);
//printf("segment = %d\n",root->segment);
//printf("root->len = %lf\n",root->len);
//printf("line[i+1].x = %lf\n",line[i+1].x);
//printf("line[i].x = %lf\n\n",line[i].x);
//ans += abs(root->len - prev);
//prev = root->len;
}
//ans += root->len;
printf("Test case #%d\n",tstcs++);
printf("Total explored area: %.2lf\n\n",ans);
}
return 0;
}
