1 #include <cstdio>
  2 #include <cstring>
  3 #include <algorithm>
  4 #include <iostream>
  5 #include <vector>
  6 #include <queue>
  7 #include <cmath>
  8 #include <set>
  9 using namespace std;
 10 
 11 #define N 105
 12 #define ll root<<1
 13 #define rr root<<1|1
 14 #define mid (a[root].l+a[root].r)/2
 15 
 16 int max(int x,int y){return x>y?x:y;}
 17 int min(int x,int y){return x<y?x:y;}
 18 int abs(int x,int y){return x<0?-x:x;}
 19 
 20 struct node{
 21     int l, r;
 22     double sum;
 23     int val;
 24 }a[N*8];
 25 
 26 struct Line{
 27     double x1, x2, y;
 28     int val;
 29     Line(){}
 30     Line(double a,double b,double c,int d){
 31         x1=a;
 32         x2=b;
 33         y=c;
 34         val=d;
 35     }
 36 }line[N*2];
 37 
 38 bool cmp(Line a,Line b){
 39     return a.y<b.y;
 40 }
 41 int n, m;
 42 double xx[N*2];
 43 
 44 int b_s(double key){
 45     int l=1, r=m;
 46     while(l<=r){
 47         int mm=(l+r)/2;
 48         if(xx[mm]==key) return mm;
 49         else if(xx[mm]>key) r=mm-1;
 50         else if(xx[mm]<key) l=mm+1;
 51     }
 52 }
 53 
 54 void build(int l,int r,int root){
 55     a[root].l=l;
 56     a[root].r=r;
 57     a[root].sum=a[root].val=0;
 58     if(l==r) return;
 59     build(l,mid,ll);
 60     build(mid+1,r,rr);
 61 }
 62 
 63 void up(int root){
 64     if(a[root].val) a[root].sum=xx[a[root].r+1]-xx[a[root].l];
 65     else if(a[root].l==a[root].r) a[root].sum=0;
 66     else a[root].sum=a[ll].sum+a[rr].sum;
 67     
 68 }
 69 
 70 void update(int l,int r,int val,int root){
 71     if(a[root].l==l&&a[root].r==r){
 72         a[root].val+=val;
 73         up(root);
 74         return;
 75     }
 76     if(l>=a[rr].l) update(l,r,val,rr);
 77     else if(r<=a[ll].r) update(l,r,val,ll);
 78     else{
 79         update(l,mid,val,ll);
 80         update(mid+1,r,val,rr);
 81     }
 82     up(root);
 83 }
 84 
 85 main()
 86 {
 87     int i, j, k;
 88     double x1, y1, x2, y2;
 89     int kase=1;
 90     while(scanf("%d",&n)==1&&n){
 91         m=1;k=0;
 92         for(i=0;i<n;i++){
 93             scanf("%lf %lf %lf %lf",&x1,&y1,&x2,&y2);
 94             line[k++]=Line(x1,x2,y1,1);
 95             line[k++]=Line(x1,x2,y2,-1);
 96             xx[m++]=x1;xx[m++]=x2;
 97         }
 98         sort(xx+1,xx+m);
 99         m=unique(xx+1,xx+m)-xx-1;
100         sort(line,line+k,cmp);
101         build(1,m,1);
102         double ans=0.0;
103         for(i=0;i<k-1;i++){
104             update(b_s(line[i].x1),b_s(line[i].x2)-1,line[i].val,1);
105             ans+=a[1].sum*(line[i+1].y-line[i].y);
106         }
107         printf("Test case #%d\n",kase++);
108         printf("Total explored area: %.2f\n\n",ans);
109     }
110 }